Getting a foot in the door. Spaces of cocaine trafficking in the Port of Rotterdam.

As an important gateway to Europe, the Port of Rotterdam is known for its high-quality facilities and efficiency, but also attracts organised crime groups who use the transatlantic legal trade flows to traffic cocaine. Based on a qualitative study, consisting of 73 interviews with public and private actors, an analysis of 10 criminal investigations and field visits to public and private organisations in the port, this article examines how organised crime groups involved in cocaine trafficking take advantage of or adapt to the socio-spatial relations in the Port of Rotterdam. First, we pay attention to which physical spaces in the port of Rotterdam provide opportunities for cocaine trafficking. Second, we examine how the occupational and legal environment in which people, private companies and law enforcement agencies in the port work and interact provide opportunities for cocaine trafficking. Our findings demonstrate that increased security measures by both public and private actors directed at physical spaces result in a displacement to new spaces in and around the port of Rotterdam. Furthermore, the current socio-spatial relations in the port of Rotterdam also make the role of people on the inside – referring to a whole range of public and private employees – increasingly indispensable.


Introduction
With a total throughput of 469.4 million tonnes and 8.781.185 containers in 2019, the port of Rotterdamalso known as Europoortis the largest harbour in Europe, and the largest in the world outside of Asia (Castelein et al. 2019: 4; Port of Rotterdam 2019: 2). The port of Rotterdam owes its competitive position to a range of factors, including its unlimited access for deep-draft vessels, good accessibility via water, rail and road, high-quality port infrastructure and efficient handling of containers and bulk goods (Port of Rotterdam 2019: 10; Van der Horst et al. 2019: 191). However, in addition to being known as the most important 'gateway to Europe' (Port of Rotterdam 2019 ;Jacobs 2000), Rotterdam is also one its main entry points for cocaine (UNODC 2018: 31-32). In 2019, a record total of 33.732 k of cocaine was seized in the port of Rotterdam, almost doubling the 2018 record amount of 19.000 kg (OM 2020).
Throughput, harbour, gateway and entry point all refer back to the etymology of the word 'port', of which the origins can be traced to the Latin 'porta', meaning gate, or the Dutch 'poort', meaning door. 1 In a recent examination of organized crime (OC), policing and security in five major seaports, Sergi (2020a: 7) notes that organized crime groups (OCG) need a 'door' to successfully secure the narcotics. Based on Sergi's (2020a) empirical description, its meaning could be taken both literally and figuratively. In addition to a port as such being a 'door' for drugs, the study of Sergi indicates that 'doors' represent physical spaces in and around the port that provide access to the imported drugs. Moreover, a 'door' in the port can also be a metaphorical reference to "someone with a useful function, corruptible for a myriad of different reasons" (Sergi 2020a: 14) who, because of his or her occupation in the port, can act as a 'door' for OCG.
Previous research has shown that the port of Rotterdam plays a central role in international drug trafficking with OCG taking advantage of its geographical and infrastructural conditions (see, among others, Farrell 1998; Fijnaut et al. 1998;Zaitch, 2002;Eski 2011;Eski and Buijt 2016;Ferwerda and Unger 2016). The Netherlands lends itself for transit crime because of its logistical infrastructure (Kleemans et al. 2002) and the port of Rotterdam "lends itself for smuggling activities" (Van de Bunt et al. 2014: 323). In this article, we build on these insights and examine the spatiality of cocaine trafficking in Rotterdam's seaport based on a qualitative study on the nature and approach of drug crime in the port of Rotterdam (reference removed for peer review) and draw on Sergi's (2020a) usages of the term 'door'. First, we take a literal reading in referring to the opportunities for cocaine trafficking provided by physical spaces in the port of Rotterdam. Secondly, we examine the metaphorical interpretation of a 'door' for drugs by focusing on how the occupational and the legal environment, in which people, private companies and law enforcement agencies in the port work and interact, provide opportunities for cocaine trafficking. We will argue that increased security measures by both public and private actors directed at physical doors result in a displacement to new spaces in and around the port of Rotterdam. Furthermore, we will argue that the current socio-spatial relations in the port of Rotterdam imply that OCG redirect their attention to a whole range of public and private employees making port employees at-risk for corruption and violence.
This article proceeds as follows. First, we provide an overview of the literature on the relation between OC and spaces and flows in ports. Second, we outline the methods used in the study. In our third section we discuss our empirical results by illustrating, on the one hand, the opportunities for cocaine smuggling provided by physical spaces in the port of Rotterdam and, on the other hand, the increased importance of people within these spaces to successfully import cocaine. The discussion reflects on the implications of our findings for both future research on organised crime and for public and private policies addressing OC in seaports.
Organised crime in flows, spaces, and ports Historically, harbours and seaports have been a décor of organised crime, illustrated by studies documenting the involvement of the 'Ndrangheta in the port of Gioia Tauro (Calabria, Italy) (Arlacchi 1986: 88-116;Sergi and Lavorgna 2016: 80-83) and racketeering by Italian American OCG at New York's Fulton Fish Market (Jacobs 1999). Transnational flows of people and goods have transformed ports to important sites for, amongst other things, human smuggling and illegal drug trafficking (Staring et al. 2005;Eski 2011). However, as Calderoni (2019: 177-178) notes, there is some debate on how OCG have dealt with these transnational flows. Castells (1998: 171), for instance, has argued that criminal organizations have benefitted from the increasingly global market and the technological developments in communication and transportation. Similarly, Shelley (2019: 223) notes a globalization of crime and an international expansion by OCG. According to Europol's most recent Serious and Organised Crime Threat Assessment (SOCTA), seven out of ten OCG are active in more than three countries (Europol 2017: 15).
However, this picture of illicit globalization "obscures as much as it reveals. It distorts and distracts as much as it informs" (Andreas 2011: 405). A mere focus on the transnational dimension of OCG risks discounting the importance of the local context in which OCG operate (Hobbs and Dunnighan 1998). According to Hobbs (1998), building on the work of Robertson (1995), metaphors of globalization fail to grasp "the complexity of local contextualities" (p. 418), especially when the global is defined as excluding the local (p. 408). Focusing on the port of Antwerp, Easton (2020: 111) notes that "glocalized" phenomena (e.g. cocaine trafficking) are inherently international, while also significantly impacting crime and crime control policies in local ports.
In criminology, the concept of embeddedness is used to signal that OC interacts with and depends on its local and social surroundings (Van de Bunt et al. 2014). Most studies on the embeddedness of OC have explored the 'relational' aspects, documenting that OC does not exist in a social vacuum but rather follows the laws of both geographical and social proximity (Kleemans and Van de Bunt 1999;Staring et al. 2005;Van de Bunt and Kleemans 2007;Kleemans and De Poot 2008;Van de Bunt et al. 2014). In addition to relational embeddedness of OC and OCG, Van de Bunt et al. (2014: 323-324) discuss 'structural' embeddedness, referring to the importance of branches of industry, occupations, communities or places. Seaports are considered examples of places where OC can be structurally embedded, but existing studies have only offered a peripheral glance at the ways in which ports impact OC and activities of OCG. Specifically, we argue that there is a need for a more concise and specific "understanding of who or what the socially embedded actors are, and in what these actors are actually embedded" (Hess 2004: 166).
In reference to international drug trafficking, structural embeddedness highlights how ports constitute hubs for legal trade flows that produce opportunities for the illicit drug trade to flourish (Eski 2011: 418;Eski 2019: 2). When global licit and illicit flows connect in seaports, specific occupations, professional contacts and the work environment can serve as a breeding ground for criminal activities (Kleemans and Van de Bunt 2008;Mars 2016). Both legitimate and criminal entrepreneurs benefit from the social interactions that take place in "seaports, customs offices, and transport firms" and from the knowledge that is gained about import and export practices (Van de Bunt et al. 2014: 328). However, this structural side of embeddedness is not contingent upon the occupations as such, but rather determined by the "intersections with legitimate activities such as the transport of goods, the transhipment of goods in ports" (Van de Bunt et al. 2014: 328).
In ports, these interfaces between legality and illegalitybetween OCG and legitimate occupations and businesses -can take many forms (Passas 2003). In some cases, OCG hide the contraband among legal products and harm the legal trader in the process, oftentimes making the products unfit for consumption (e.g. in case of food). In other examples, the relationships are cooperative with the trader or shipping agent knowingly facilitating the trafficking and thus involving corruption. Different studies have documented the role of corruption in smuggling operations in ports (Kostakos and Antonopoulos 2010;Eski & Buijt 2016;Sergi 2020a). However, as Kleemans (2014: 47) notes, corruption is not a prerequisite for these transit crimes. A previous study on drug trafficking in the Netherland, based on an analysis of 15 Dutch cocaine trafficking cases from the late 1990s and early 2000s, illustrated that corrupting custom officials was deemed unnecessary to successfully import cocaine because the chances of getting caught red-handed were low (Kleemans et al. 2002: 94). Moreover, Zaitch (2002: 254), in his ethnographic study on Colombian cocaine traffickers, also found that most smuggling strategies of Colombian related cases were geared towards evading controls in ports and did not involve corruption of Dutch customs or police. However, times seem to have changed. A recent analysis of 16 Dutch drug trafficking cases via Schiphol airport or the port of Rotterdam indicated that corruption was frequently used by OCG to neutralise security checks (Madarie and Kruisbergen 2019: 39). In recent years, several high-profile corruption cases happened at the respective customs departments of the ports of Rotterdam (Eski and Buijt 2016).
Our literature overview indicates that seaports facilitate flows of illicit goods because of their logistical infrastructure and strategic location on major migratory and trade routes, thus making them ideal spaces for criminal groups to operate in (Ruggiero 2014: 154). This results in the embeddedness of both criminal activities and OCG in these spaces (Fijnaut et al. 1998; Van de Bunt et al. 2014;Eski 2015;Madarie and Kruisbergen 2019;Sergi 2020a, b). Apart from some notable exceptions (Eski 2015;Easton 2020;Sergi 2020a, b), ports have remained understudied as the central locality of empirical research on OC. Therefore, by drawing on a qualitative study on cocaine trafficking in the port of Rotterdam, we aim to contribute to an improved understanding of how the dynamics of global licit and illicit flows impact local spaces, occupations, criminal activities, and crime control policies.

Methods
Our analysis uses a qualitative methodology which combines different methods of data gathering. We started with an extensive review of academic literature, statistics, policy papers and media reports. Second, 75 individual and 3 group interviews 2 were conducted with representatives of public sector organizations, as well as representatives of private companies that have a direct relationship with the port of Rotterdam. Most of the interviews took place in the Netherlands, but we also interviewed representatives of public and private sector organizations during visits to Antwerp and Hamburg as well as via videoconferencing with key informants in Latin America. In addition, we visited various public authorities and private companies in the ports of Rotterdam, Antwerp and Hamburg and attended meetings and training sessions of relevance to the control of drug trafficking and other crimes in the port. These working visits and observations occurred between January 2018 and March 2019 and allowed gaining insights into the actual working methods and situational differences of different actors.
Third, we were granted permission by the Dutch Public Prosecution Service to study criminal investigations into the trafficking of cocaine in the port of Rotterdam. In absence of a central registry, a snowball method based on a consultation of experts working at the police and the Public Prosecution Service led to a selection of 10 cases with a wide range of smuggling methods (modus operandi) and partnerships. These investigations occurred between 2013 and 2017. More recent cases were excluded because trial was pending. These police investigations contain a wealth of informationsometimes thousands of pages per case -because of the use of special investigative methods, such as wired taps, IP taps, and interrogations. An analytical framework was used to systematize the data-analysis. The cases are listed in Table 1. Because of possible recognizability and traceability of suspects, companies or specific locations, the criminal investigations bear a fictitious name and some elements of our description are presented at an aggregated level.
Using these different methods provided us with complementary perspectives about cocaine trafficking in the port of Rotterdam. The police investigations shed light on the spaces used by OCG to import cocaine, whereas the interviews and observations provided insight into the lived experience of policing cocaine trafficking in the port of Rotterdam. After familiarization with the empirical data, two researchers started with reviewing the data and assigning initial thematic codes based on the conceptual framework and research questions across the dataset in Atlas.ti 8 for the central themes. During this deductive process, they discussed and realigned their interpretation and use of codes with other members of the research team. The two initial coders then continued the analysis by an inductive open coding strategy, identifying the underlying and new themes that came out of the data. To ensure consistency within each theme and across the dataset and thereby increasing reliability of the analysis, this last coding strategy was also reviewed by the research team (Miles and Huberman 1994: 59-61).

Research setting
From a small medieval city at the mouth of the river Maas, Rotterdam has transformed into a global city, with its development inextricably linked to the development of the port (Eski 2015: 28-30). Throughout most of Rotterdam's history, "waterfronts and harbours were located in the heart of the city or its nearby peripheries" (Kermani et al. 2020: 347), making the port and the city indistinguishable. To answer to the growing need for large-scale modernized terminals and port facilities with excellent access to sea, road and rail transport and minimal pollution for nearby residential areas, the port of Rotterdam expanded westward (to the sea) with the development of the areas Europoort and Maasvlakte I and II (Aarts et al. 2012: 7). This is visible in Map 1: Port of Rotterdam. Most of the (container) terminals left the original city ports for stateof-the-art facilities at the deep-water quays of the Maasvlakte. Nowadays, the port of Rotterdam operates 24/7 and stretches 42 km from the city centre all the way to

Results
In this section, we examine how organised crime groups involved in cocaine trafficking take advantage of or adapt to the socio-spatial relations in the Port of Rotterdam. We analyse how structural embeddedness plays a role ( Van de Bunt et al. 2014) and continue the above-mentioned metaphor of 'doors' to the port (Sergi, 2020a). First, we focus on which physical spaces provide opportunities for cocaine trafficking. Second, we emphasise the importance of access to these spaces and to information by way of people on the inside.

Fruit warehouses, empty depots and container terminals as 'doors'
OCG make use of different drugs smuggling methods: hidden in hollowed out fruits, banana boxes, engines or other products; concealed in the walls, ceilings or floors of containers; hidden in the inspection hatches of the engine compartment of reefers (refrigerated containers); dropped off at sea after being hidden on board of large seavessels; smuggled underneath the waterline in intricate constructions welded to ships; packed in carryalls placed near the doors of containers, which are then taken out of the container and driven off the terminal (so called 'rip-off' method) (Eski and Buijt 2016: 373;Boerman et al. 2017: 36;Colman 2018: 131). This non-exhaustive overview of modus operandi of cocaine trafficking shows that OCG potentially use a wide array of maritime smuggling methods to (ab)use Rotterdam's licit trade flows. In an area scan by the Rotterdam Seaport Police (2018: 26) and during our interviews it was noted that the rip-off method and the method of hiding cocaine in the frame or engine compartment of reefer containers were popular methods. Because Rotterdam is the first port of call for most shipping lines from Latin America, these trade routes are Europe's link with the primary source and transit "What you mainly see is that -and granted I probably don't know everythingbut the branches that are most vulnerable for drug trafficking are mainly the container terminals. Recently, also the empty depots and fruit and vegetables [warehouses] could be added to that list. Ultimately, that has to do with the countries of origin, of course". (R71) The choice of smuggling method determines which spaces in the port of Rotterdam are confronted with cocaine trafficking. Based on the most popular modus operandi used by OCG in Rotterdam, three physical 'doors' for the trafficking of cocaine in the port of Rotterdam can be distinguished: fruit warehouses, empty depots, and container terminals.
First, fruit terminals and warehousespredominantly located in the Rotterdam city ports, particularly the Merwehaven and Vierhavens areasare contemporary spaces that provide opportunities for cocaine trafficking. Fruit is often used to smuggle drugs, hidden within the pallets, boxes or fruit itself. One of the police investigations illustrates this: "On [date], an employee discovered that the lock of the entrance door to the storage facility has disappeared and that about 30 boxes have been moved from the rear row in rack M. An investigation has shown that four boxes have a lighter weight compared to the bill of lading and about 40 kilograms of bananas are missing." (Mizzenmast case) This case shows how the local handling of fruit results in a 'door': a specific spatial concentration of opportunities for the trafficking of cocaine. Burglars enter these fruit warehouses to secure the drugs, often rendering some of the product unfit for consumption. However, the problems with cocaine trafficking via fruit import also extend beyond the port itself, reaching terminals and warehouses in the hinterland after the drugs have successfully passed through the port.
Second, the so-called empty depots are important spaces that provide opportunities for cocaine trafficking. Empty depots store used containers and provide container cleaning and repair services. The 22 container depots in and around the port of Rotterdam cover over 120 ha. Our respondents indicate that empty depots are increasingly used by OCG to secure cocaine from the frames of containers: "The empty depots are good examples. You also have one in Waalhaven. (...) Every time we are there, we find new holes in the fences and tools to demolish entire containers. Not too long ago, we arrested a lot of people there and things got so heated that a colleague had to draw his firearm. We arrested someone who is a well-known [picker]. 3 (R52).
In general, the security measures at these empty depots are limited, in some cases even absent. Most operate only during the day, leaving the locations practically empty at night. According to one of our respondents, security is not considered an issue "because they store empty containers, who comes to steal an empty container?" (R17). Or as a manager of a container depot explained: "We don't have surveillance. It is open. It is an open area, because we store empty containers. Once there is a load, it will still be closed ground. ( …) If you have an ISPS 4 status or AEO 5 status, the area needs to be closed but we have neither, so it is freely accessible. Everyone can get on and off the depot." (R20) This specific container depot has recently moved to a location on a container terminal and is therefore also subject to both ISPS and AEO regulations. The opportunities for drug trafficking regarding access to the location has changed, which our respondent welcomed, although "(they) can still break in of course, but there are more cameras and there are security guards" (R20).
In some cases, empty depots also play a role in providing OCG access to neighbouring container terminalsthe third physical 'door'as is illustrated in one of the police investigations: "Company A is a container terminal with direct access to the sea in the city port of Rotterdam., It has an annual transshipment capacity of more than 1,000,000 TEU 6 and has 1500 reefer connections. The terminal has three piers, each 800 meters long. Generally, sea-bound vessels from South and Central America arrive at company A on Friday after which the containers are transferred to the reefer stack on one of the piers. During the weekends, the reefer containers remain at the terminal because road transports starts on Monday after 3:00 AM. The reefer stack is almost immediately adjacent to the empty depot of company B, separated only by a fence and a roadway. Regularly, intruders cut holes in this fence in order to get into the stack and remove cocaine from the reefers." (Dodger case) Whereas the terminals in the city ports offer specific opportunities for OCG because these sites are located near the city centre, the Maasvlakte appeals to cocaine smugglers because it offers a certain level of anonymity and an ideal escape route via the A15 motorway. However, in contrast to the container sites in the city ports, the daily container volume handled at Maasvlakte terminals is significantly higher, resulting in long stacks of almost three kilometres. Moreover, as the following case illustrates, the way these container terminals work provides additional challenges for OCG using the rip-off modus operandi: "To get to a container in stack D at container terminal C, an individual must deviate from the road used by workers and drive or walk through a carrier area that has forklifts of 12 meters high. For safety reasons, it is strictly forbidden to walk or drive in a car in this area. Container stack D can be reached after passing the carrier area, but for safety reasons only reefer mechanics can enter stack D." (Oakum case).
In general, the container terminals on the Maasvlakte have implemented more and better crime prevention measures through environmental design compared to the container terminals in the city ports. These measures include entrance gates, qualified security guards in the porter's lodge, surveillance vehicles on site and extensive camera surveillance, making these spaces less accessible for OCG. These container terminals, represented by their security officers, also share information on cases and security measures in the six-weekly meetings of the Information Sharing Centre, 7 a private-public cooperation which also brings the Seaport Police and Customs around the table.
Another substantial difference between the city ports and the terminals on the Maasvlakte II is the automation of logistical processes. According to some of our respondents, there are only a few incidents related to cocaine trafficking at these terminals, because people cannot access the container stacks within this "fully fenced and high-tech environment" (R65). However, the automatized terminals might create new vulnerabilities for hacking by criminal organizations. Leukfeldt et al. (2019: 334) indeed describe a drug trafficking case of hackers who aided in locating and picking-up containers in a port before the regular transport company reached the cargo. Although respondents raised it as a potential opportunity, 8 we did not encounter hacking of business processes in the case files nor were concrete cases of hacking to facilitate drug trafficking mentioned during the interviews.

Employees of public and private port organisations (re)creating 'doors'
In the previous section, we showed how cocaine traffickers make use of opportunities provided by legal trade flows and use different 'physical doors' depending on the smuggling methods. Knowledge about logistical processes in the port as well as familiarity with security measures at port sites are paramount for OCG to successfully make use of the opportunities provided by spaces such as terminals, emptydepots and warehouses in the port of Rotterdam. Because of break-ins, damaged fences and intruders in the stacks, many of these locations have sharpened their security measures, in an attempt to close these doors for OCG. However, OCG still manage to get a foot in the door, specifically by redirecting their focus to port employees.
First, to keep unauthorized people out, many port sites have checks at the entrance gate. However, many people have legitimate reasons to access these ports: a wide range of employees of port companies, including but not limited to lashers, surveyors, stevedores, straddle carrier drivers, technicians, and truck drivers, as well as different government agencies and semi-public actors, like the boatsmen and pilots. Most are granted access with personalised, sometimes biometrical, access cards. For OCG, as different respondents noted, these access cards are a sought-after commodity, estimating their value between 5.000 and 15.000 euro. In the Oakum police investigation, several local suspects actively searched for port employees or people with port access cards within their social networks such as the Rotterdam neighbourhoods they grew up or resided in. The core members of the criminal network paid these port employees about 8.000 euro for an access card. Furthermore, they also used other ways to enter the gated terminals: "The services of M., K's brother in law, are used. M. is a shift leader at [company in the port], which is located next to the [container terminal]. The sites are connected by a so-called internal lane, solely intended for commercial vehicles and so-called container trains. This internal lane has barriers to prevent access from the public road. [Company name] has two company cars, equipped with transponders that give access to the internal lane. This internal lane provides access to the business site of the [container terminal] but also gets you close to the container stack. These company cars may only be used by shift leaders and their superiors. They have two seats in the front and a cargo box without windows in the back." (Oakum case) Moreover, our respondents indicated that some OCG gain access to port sites by using forged vehicles that closely resemble company cars and even "a customs vehicle was duplicated" (R52). Additionally, members of OCG wear clothing of port employees, including reflective vests, safety helmets and overalls with logos of the companies. In the Mizzenmast case, clothing from different port companies was found during a search at a suspect's house. Aware of these practices, a maritime pilot told us that he burns his company clothing instead of throwing them out in the trash after they are replaced with new ones.
Often, entering these locations by means of access cards, forged vehicles or clothing alone does not guarantee that OCG will be successful in securing the cocaine. Because of the size of the Maasvlakte sites, locating a container with a specific number is searching for the proverbial needle in a haystack. Therefore, in addition to physical access to locations, knowledge is key as one of the interviewees (R05) noted: "You must have information. It's always about access.". Many port employees have access to the specific number and location of containers during its handling. In the container logistics sector, it is seen as a customer service that containers can be followed via a track and trace systemeven down to the level of the row and height in the stacks. For some occupations in the port, this (potential) access to stack information and additional knowledge about the logistics process, constitutes an important vulnerability, as one of our respondents noted: "If you already have access to the system [with information about cargo and stack information], then you actually already have a lot. (…) There are so many possibilities to obtain that information. As a result, you also have that very large group that could be vulnerable and that often also means that many of those employees at a terminal actually fall into this at-risk group, right?" (R10) Earlier studies on drug trafficking in the port of Rotterdam already illustrated that a substantial numbers of actors in the supply chainincluding planners, shippers, drivers, freight forwarders, and different employees who process documents (e.g. bill of lading)can access systems with information about the whereabouts of containers (Smits 2014: 26;Eski and Buijt 2016). However, accessing this information is not a prerequisite to perform specific jobs, like one of the respondents stated: "If I am a crane operator or maintenance engineer or doorman, why do I have to know where that container is?" (R29). For OCG, this information is very valuable and something they actively pursue. Transport company employees who were interviewed, disclosed that they had been approached by OCG, either for the theft of cargo or for locating drugs.
During the interviews, our respondents noted that in virtually every case of drug trafficking in the port of Rotterdam, they came across corruption by employees of either public or private port organisations. One respondent simply said the organization of drug trafficking "is always with someone on the inside" (R28). Similarly, there was an indication of corruption in all the police investigations we studied, either passively by passing on information about the whereabouts of ships or containers or, more actively, by lending out their access cards or otherwise facilitating access. In the Mizzenmast case, one of the suspects actively searches for contacts in a fruit import company, whereas in the Weatherly case several fruit companies play an essential role in the narcotics trafficking although it remains unclear whether these companies or their employees were knowingly involved. Case Scuttlebutt makes clear how essential the knowledge, contacts and expertise of these facilitators are: an employee of a fruit import company attempts to smuggle narcotics from Central America by using existing trade lines to the Netherlands. Furthermore, the Mizzenmast case illustrates that port employees have vital insights into how to bypass site security or government supervision, as is indicated by the following wiretapped conversation between an employee of a container terminal (E) and a suspect (F): "E: For example, if you are on our port site and you want to leave, you also have to drive through that scan. F: Seriously? E: Yes, yes, yes, soon there will be mobile scans on the site that you have to pass. The trucks must go through, everything that enters the site must go through. It's not ready yet, but I'll let you know" (Mizzenmast case) Based on frequent contacts with port employees, either in person or by phone, the suspect was kept informed about the construction of scans, but also about the specific container handling procedures at different terminals.
The Fiddly case offers an example of a port employee who plays an even more active role to make sure cocaine passes through the port of Rotterdam. As a planner working at a large container terminal in the Maasvlakte, this port employee was informed about upcoming inspections by the custom department. One day, the planner receives an email about a planned rip-off inspection taking place, including an overview of the specific containers that will be checked. During the police investigation, it became clear that the planner used his personal account to move a specific container to a different stack, outside of the area with containers selected for customs control. However, this manoeuvre by the planner did not prevent the inspection by the custom department, it just delayed the process. During the check, 700 kg of cocaine were found in the container that was relocated by the planner. A similar but this time public sector port employee featured in the Weatherly case: a customs officer, working as a selector at the pre-arrival department. As the human factor in the container selection process, the customs officer was able to influence which containers should be checked and in what manner: either on paper, by scan or by way of a physical inspection. Over the course of several months, he would earn a generous fee by checking the whereabouts and status of specific containers and by making sure some would be kept out of inspection, for instance by changing the containers' status in the customs systems. Moreover, because of his occupation, the main suspect had insights into the risk profiles that underlie the selection process of the customs department, information he allegedly shared with OCG.
These examples illustrate that corruption of port employees is essential for OCG, especially to reopen or bypass closed physical doors or to use the spaces to get a foot in the door in the port of Rotterdam. In some of the cases we studied, we see OCG and port employees cooperating with the latter financially profiting from their involvement. However, our respondents also mentioned the use of violence and intimidation towards port employees. Although this use of violence was often mentioned during our interviews and during the training sessions for private port employees we attended, we only came across one threat of violence in one of the police investigations we studied. In the Dodger case, one of the main suspects claimed that he cooperated with an OCG by giving information about the port company he worked for because he was threatened at gun point.

Discussion
In this article, we examined the spatiality of cocaine trafficking in the port of Rotterdam. Our study illustrates that intertwining global licit and illicit flows impact specific localities and businesses in Rotterdam's harbour area. Although cocaine traffickers ride along with the legal trade flows, their choices of routes and locations to enter ports are dependent on the supervision and the control in the overall port area as well as in specific locations within the ports (cf. Sergi 2020b: 13-14). Specifically, drawing on Sergi's (2020a) use of the term 'door', we identified three spaces in the port of Rotterdam that are used by OCG as physical 'doors' to successfully import cocaine: fruit warehouses, empty depots and container terminals. These port companies are specific examples of places where OC is structurally embedded, both in terms of the location and situational conditions and in terms of the occupations that frequent these spaces (Van de Bunt et al. 2014). We demonstrated that these three spaces go hand in hand with specific modus operandi of hiding narcotics within fruit, fruit boxes or pallets (fruit warehouses), hiding in walls, ceilings or floors of containers or engine compartments of reefers (empty depots) and rip-off (container terminals). Because our methodology consisted of analysing police investigations and interviewing public and private actors, it should be noted that these three are by no means the only physical 'doors' nor the only modus operandi used by OCG to import cocaine via the port of Rotterdam. Other research methods, for instance interviewing active, convicted or former cocaine traffickers, could shed light on opportunities provided by other physical locations.
Moreover, these geographic locations are by no means fixed spaces, but rather, concordant with Sergi's (2020a: 14) main findings, a temporary outcome of an arms race between OCG and public and private actors in the port of Rotterdam. Although situational measures attempt to take away opportunities for drug trafficking, not all vulnerabilities and opportunities for drug trafficking in the port of Rotterdam can adequately be addressed. For instance, our respondents noted that the emergence of empty depots as 'doors' might have been a result of increased safety measures on container terminal sites. Raising barriers for one spatial opportunity, therefore, might lead to OCG trying to get a foot in the door in other parts of the port in Rotterdam.
Furthermore, our study suggests that an even more problematic and unforeseen side effect might not just be geographic displacement of 'doors' for cocaine trafficking, but rather a shift towards the port employees. A wide range of port employees have physical access to port sites, an understanding of the intricacies of port logistics, as well as detailed knowledge about container numbers and locations and security measures and supervision. In all the police investigations we studied, port employees, working either for port companies or government agencies, were involved in cocaine trafficking. As we illustrated, these examples include port employees actively assisting OCG by bypassing security checks or relocating containers, but we also came across more passive ways of facilitating OCG by, for instance, providing information or access cards. Public and private organizations in the port of Rotterdam have raised barriers for drugs trafficking by means of increased supervision and automation of the logistics process, but this has also made it more difficult for OCG to import cocaine without having a foot in the door in these same organizations. Future research should further scrutinize these relationships between OCG and port employees, in addition to shedding more light on the ways in which port employees get involved with and approached by OCG.
Finally, global trade flows undoubtedly impact cocaine traffickers on a macro level, but our analysis shows how there are variations in opportunities within and between physical locations in local ports depending on the private security measures or the public supervision, or the absence thereof. Areas in the port of Rotterdam which are located closer to the city face different challenges regarding cocaine trafficking than port areas on the Maasvlakte. This is a result of a combination of the physical lay-out of the port area, its proximity to the city, the type of economic activity and the security measures that are in place. Hence, the prevention and control of cocaine trafficking requires a tailored approach based on this combination of factors. Besides, we mentioned that security officers of container terminals, Seaport Police and Customs meet in the Information Sharing Centre. This public-private network allowed coordinating security measures at the terminals but might have resulted in smugglers choosing other modus operandi to secure their cocaine and thus targeting other port facilities, later in the logistical process (i.e. empty depots and warehouses). Therefore, alignment between different areas within the same port can avoid that increased security measures in one port space result in increased cocaine trafficking in another. However, these dynamics of displacement are not limited to the port of Rotterdam. With opportunities to successfully import cocaine into the port of Rotterdam changing because of situational crime prevention measures, other harbours in the vicinity, like the port of Antwerp (De Middeleer et al. 2018: 261;Easton 2020), Hamburg (Eski 2015), or other ports in Europe might be targeted by OCG. Equally, increased security measures in other European ports might impact the import of cocaine in Rotterdam. This implies that communication between ports about security measures -even when they compete for maritime-based tradecan foster better coordination of prevention and control policies for drug trafficking. Alignment between port security policies within and between ports can avoid a fragmented perspective and an unlevel playing field which play into the hands of OCG (Sergi 2020a). However, the extent to which this alignment can be achieved depends on how economic and security interests are weighed. Efforts to close doors through improved physical and digital security measures as well as attention for screening, awareness and resilience of public and private port employees puts pressure on the efficiency of the logistical process while answering to societal expectations of increased engagement with security in ports.
Second, the researchers have all applied for and received a Certificate of Conduct (VOG -Verklaring Omtrent het Gedrag). A certificate of conduct is a document on behalf of the Dutch Minister of Legal Protection declaring that the applicant has not been convicted for any crime registered in the Dutch Criminal Records System or police files that is relevant to the performance of his or her duties. 9 In addition to the VOG and PaG statement, all members of the research team as well as the transcriber have signed a so-called "Integrity and confidentiality statement" from the Municipality of Rotterdam. Finally, as employees of Erasmus University Rotterdam they agreed with the Netherlands Code of Conduct for Research Integrity. 10 Third, this research was supervised by an advisory commission of experts from practice and chaired by an academic specialist in the field of organized crime Prof. dr. Hans Nelen (Maastricht University). This committee provided regular feedback on methodological issues as well as (preliminary) results during the research. Members of this committee also screened the final manuscript on anonymity and confidentiality of the respondents before publication. Fourth, in order to exchange confidential documents between the researchers and the public authorities working in the harbour, the Regional Information and Expertise Center (RIEC) made a FileShare server available in which all registered parties involved in the research team and the supervisory committee could log in with a password and an additional code sent by text message to upload and download files. Fifth, to guarantee secure research data management, handling and storage, Erasmus University Rotterdam is compliant with the General Data Protection Regulation (GDPR). To this end, the university applies the principles of privacy by design and privacy by default in the research design. An end-to-end encrypted and ISO 27001 certified data vault was used for the research. This data vault is based on the BlackBerry Workspaces (see also: https://www.youtube.com/watch?v=WiTZAvegfS0). In this data vault, the researchers work safely together with the highest data classification, similar to what the Dutch Intelligence Service (AIVD) uses. In the data vault, researchers have access to a wide range of extensive file protection and encryption, logging and monitoring of usage and controlled access. The results of the analysis of our observations, documents and interviews were only reported confidentially and at an aggregated level, without disclosing the name of our respondents.
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