What should the checkpoint response be when either a technology alarms – indicating the potential presence of a prohibited/restricted item – or concerns exist about a passenger or employee and, in either case, the physical pat-down search does not reveal any item? Technology can only go so far; ultimately it is up to a human being to make a decision based on a full risk assessment. Alexandra James discusses the sensitive subject of strip search, and under what circumstances, in an airport environment, such a search can be carried out. She considers operational protocols – number of searchers, witnesses, respect for the passenger or staff member – which need to be defined before considering the practical methods of conducting the search.

Despite the advances being made in passenger screening technology, airport screeners sometimes have to be prepared to conduct physical inspections of passengers’ bodies and/or their underclothing prior to admitting them into sterile areas of the terminal; in extreme circumstances, a ‘strip search’ may be warranted. While necessary for the resolution of alarms and general suspicion surrounding certain passengers, this level of passenger search may be particularly intrusive and therefore raises serious ethical and procedural issues.

The search process involving the removal of clothing is frequently referred to generally as ‘strip search’ but the terminology differs between countries and also sectors (i.e. between aviation, prison and law enforcement settings). In the UK aviation sector, ‘enhanced hand search’ refers to a search involving the removal of clothing as far as the underwear (which is the limit of any search in the UK performed by airport or contract screening personnel) while ‘strip search’ is used by UK police to refer to any search procedure involving the removal of underwear. For the purposes of this article, the term ‘strip search’ will be used to refer to the various stages of passenger search, from removal of intermediate layers (shirt, trousers, etc.) up to (but not including) the point where hands-on physical inspection is required by medically qualified personnel.

In addition to variance on what the process should be called, there is also some disagreement globally over how thorough searches can legitimately be, who should conduct them past a certain point, and even whether strip searches should be conducted at all. In the UK, any alarm that cannot be resolved by removing clothes up to the ‘penultimate’ layer (i.e. underwear) should be escalated to a search on police premises. Similarly, responding to press enquiries regarding two lawsuits filed by passengers in the United States last year, the Transportation Security Administration claimed that it does not conduct strip searches ‘in any case’. For this reason, contract screening companies who specify strip search within their standard operating procedures (SOPs) should consult their legal advisors to ensure they are complying with local law.

In the aviation security setting, searches involving the removal of clothing are rarely conducted and would not (should not!) be considered ‘routine’ – but rather a last resort. This factor, in addition to the fact that they are procedures requiring high levels of privacy and sensitivity means there is little opportunity for personnel to gain experience or training on the job, and there are obvious practical challenges associated with addressing the topic in the classroom. Additionally, as with many issues currently faced by the industry, aviation suffers from a lack of specific universal guidance on conducting strip searches, resulting in vague or varying legislation across regions and airports. For these reasons, the aviation security industry needs to learn lessons from settings in which strip searches occur more frequently, such as customs, law enforcement and prisons. I have discussed the subject with a range of experts from various countries and backgrounds and amalgamated their views in order to present a ‘best practice’ roadmap, from justifying a strip search to the procedure itself, and the issues that should be taken into consideration while a search is being conducted.

Justifying a Search

Across aviation, customs and law enforcement settings, a strip search involving the removal of clothing beyond the outer layer must be fully justified. The phrase often used is ‘real’ or ‘reasonable suspicion’, i.e. screening officers must have reasonable grounds to suspect a passenger is concealing a prohibited item on (or within) their person. But what does this mean on a practical level? Reasonable suspicion is a highly contentious and subjective concept, which by itself could form the basis of an article.

In recent years, technology has, to a certain extent, assisted by providing definitive, auditory or visual indicators of potential concealments. But technology has its limitations, and the cost of implementing high-tech measures can be prohibitive. Smaller, regional airports with more limited screening facilities may therefore depend more heavily on manually searching passengers. On the other hand, fewer machines may mean fewer alarms requiring manual resolution. At any rate, we should always be wary of depending solely on machines when making decisions about whether a passenger poses a risk. Our colleagues engaged in border controls provide excellent examples on a daily basis of how low-tech measures such as behaviour analysis can be effectively implemented to identify those who may be carrying prohibited items. Each civil aviation authority should have its own list of suspicious indicators to allow passengers’ behaviour to be translated into tangible ‘alarms’, thereby providing (relatively) objective, and more importantly, documentable justification for search.

“…each civil aviation authority should have its own list of suspicious indicators to allow passengers’ behaviour to be translated into tangible ‘alarms’…”

A strip search is generally justified if concern regarding a passenger – whether founded on a technological alarm or other suspicious indicator – cannot be resolved via a less intrusive secondary search. We should therefore take a ‘stepwise’ approach to resolving alarms, whereby the passenger is escalated through various stages of the resolution process – from least intrusive (general search of personal belongings, archway metal detector, etc.) through secondary measures (e.g. pat-down, questioning, etc.) to more intrusive measures (strip search). In some countries, the maximally invasive procedure is an intimate/cavity search; however, whilst this may be acceptable management of risk in a prison environment, most aviation authorities do not even permit searches involving the removal of undergarments, let alone cavity searches. Regardless, where alarms cannot be resolved, the airline or airport should simply deny boarding. In such cases, and if the person is not referred to law enforcement, we cannot ignore the possibility that an individual with negative intent may return and attempt to travel on a different flight or another carrier, as Richard Reid (a.k.a. ‘the shoebomber’) did in Paris in December 2001.


Good communication is vital in all interactions with passengers, but especially when an individual is pulled aside for secondary screening or a strip search. In addition to making the passenger feel more comfortable while they are in what they may perceive to be a highly vulnerable situation, some alarms may be resolved more easily if the concern is explained clearly. Sara Gilmore of Kerwin Consulting previously worked for Her Majesty’s Prison Service in the UK but now has 27 years’ experience working in aviation. She acknowledges the importance of communication in both settings: “The best searchers I have known in both the prison service and airport/airline security industry are those who possess excellent customer service and communication skills – getting the individual ‘on side’ makes the process a lot easier”.

If secondary screening fails to resolve an alarm and it is determined that the passenger should undergo a strip search, the procedure should be clearly explained and – initially – verbal consent obtained either from the passenger or a guardian. Travis Jones, security and resiliency specialist at Datum Services in Australia and previously head of security at Melbourne Airport, suggests that if good communication is used throughout the early stages of the screening process, most passengers are willing to submit to further searches: “In my experience, the absolute majority of people have no issue with the search process, be it private or otherwise, once it is clearly explained to them in a manner that allows them, or their guardian, to fully understand the procedure and appreciate the level of control they maintain throughout the highly structured process”.

Control is a significant element of the search process. At every stage, it is important that the passenger is viewed and spoken to as a customer – not a suspect. In stark contrast to a prison or law enforcement setting, when it comes to civil aviation pre-flight screening, every individual has the right to refuse a search, and no-one should be searched by force. Any action should therefore be requested by screening officers, and not demanded. However, it should be made clear that the passenger will be denied access to airside and therefore, ultimately, to their flight if an alarm cannot be resolved.

Communication: Social Sensitivities

For many people, removing items of clothing in front of another can be a very challenging experience, but even more so for those with certain social sensitivities. These may include body disfigurations, religious sensitivities (e.g. if a passenger is asked to remove an item of religious significance, such as a Sikh turban or Muslim niqab) or due to gender identity. For example, the person may be transgender, which can raise issues around whether they should be searched by a male or female member of staff (in this case, the passenger should always be asked what they would be most comfortable with). Additionally, before asking the passenger to remove any intermediate item of clothing, they should first be asked whether they are wearing undergarments, such as a bra (in certain locations, the strip search must not reveal genitalia).

“…removing items of clothing in front of another can be a very challenging experience…”

If it is determined that a search of the genital area is required to resolve an alarm (and is within local legal boundaries) and the passenger in question is a woman of childbearing age, it would be appropriate for the female screening officer to ask if the passenger is menstruating and/or wearing a sanitary towel. Treating such issues as the normal, everyday occurrences they are will, in most cases, help to alleviate embarrassment and aid communication.

Once the process has clearly been explained and verbal consent obtained, all passengers should be asked – confidentially – whether they have any special concerns about being searched that should be taken into consideration. This allows an opportunity for issues to be raised. In some cases, the discussion of a sensitive issue may even go some way to resolving the alarm. For example, a transgender woman who is biologically male may set off a millimetre-wave body scanner since the presence of her penis would not conform to the binary settings of the machine.

Search Protocol

Once the procedure has been explained to the passenger (or their guardian) and verbal consent has been obtained, the passenger should be asked if they would like one of their travelling party to accompany them as a companion/witness (if available). They should then be invited to a private screening room where written consent forms should be completed.

The search must be conducted by two officers of the same gender as the passenger. Sara Gilmore suggests that if there is a suspicion of concealment then the second person in attendance should be a supervisor, also of the same gender as the passenger, if possible: “I found that this ensured clearer communication. It also sent an escalation message to the passenger – at this point many would confess they were hiding something, usually drugs, cash or liquids”.

Search Protocol: Passenger Dignity

As previously mentioned, many people may feel particularly vulnerable during a strip search, so it is important the passenger retains a sense of control over the process. For this reason, the physical removal of any items of clothing should be completed by the passenger – never the screening officer – unless the individual explicitly requests assistance. If certain areas of the body are not viewable even when naked – e.g. beneath long hair, breasts or folds of fat, or in the intergluteal cleft – it should be the passenger who touches their own body, rather than the screener, to enable inspection by the officer from a distance.

An image from Nuctech's HT2100 dual-view X-ray body scanner (Credit: Nuctech)
An image from Nuctech’s HT2100 dual-view X-ray body scanner (Credit: Nuctech)

As discussed, all searches must be fully justified and must aim to resolve a specific alarm. If more than one part of the body must be searched, in particular the breasts, buttocks or genitals, then only one area should be exposed at a time so the passenger is never fully naked. The passenger should only be requested to remove the items necessary to resolve the alarm, and no more. This is fairly straight-forward when the search has been prompted by a specific anomaly detected by, for example, a millimetre wave body scan or manual pat-down; however, it may be more complicated if a general body search is required in order to resolve, for example, concern regarding the passenger’s behaviour, in which case the entire body may need to be inspected. If possible, any items of clothing removed should be thoroughly searched before attention is paid to the passenger’s body. Screening officers should feel for items stitched into seams, waistbands or concealed within folds and linings.

“…transmission X-ray is often deployed at airports by customs agencies, but this will usually be found in arrivals halls, rather than departures…”

It should go without saying that the officers conducting the search must act with high levels of professionalism at all times, regardless of whether the passenger is wearing Spiderman underwear, a chastity belt, or has a genital piercing (incidentally, the latter is a fairly common cause of alarms requiring resolution by strip search).

Norman Shanks of Norman Shanks Associates International, and previously head of group security for British Airports Authority (BAA), suggests that the use of CCTV in private search cubicles may be one way to ensure the professionalism – as well as the safety – of staff during searches: “There is good justification for CCTV to be used to monitor the area to avoid complaints of inappropriate touching or ‘forcing’ removal of certain items of clothing”. However, this raises significant issues, which have been deemed to outweigh the benefit in most regions: “Normally, CCTV would not be used in a private search cubicle for fear of infringement of civil liberties,” continued Shanks. “There is one major concern with the use of CCTV under these circumstances and that is the ‘security’ of the footage, which may fall into the wrong hands or be broadcasted in the media, particularly if the passenger in the private search cubicle is a well-known celebrity.”

Search Protocol: Intimate/Cavity Searches

As demonstrated by prison, law enforcement and border force settings, we cannot ignore the fact that body cavities are, and will continue to be, used by individuals to conceal weapons or restricted items. However, in many countries, including the UK, strip search is limited to visual inspection only, and manual cavity searches are not permitted. If the passenger is suspected of internally carrying prohibited items or substances then they are usually referred to a medical unit for further inspection via law enforcement or one of the governmental border security agencies.

There is a tendency to consider internal concealments as a border control issue since the vast majority are drugs- rather than weapons-related. However, as security professionals, it is our duty to acknowledge the weaknesses in our screening protocols. Currently, no technology deployed in aviation security settings is capable of detecting internally concealed items. While the threat posed by body cavity bombers appears to have subsided since the first half of the last decade, Michael Cardash, former head of the Israel National Police bomb unit acknowledges “aviation has always been a priority target for terrorist groups, and probably will remain high on the list in the future”.

The potential for carrying weapons inside rectal or vaginal cavities should, therefore, not be overlooked – and neither should the possibility for an individual to internally conceal bomb components through security screening in order for them to be removed, assembled and detonated on a flight or in a secure part of the airport terminal. The technology to identify such threats, such as transmission X-ray, is often deployed at airports by customs agencies, but this will usually be found in arrivals halls, rather than departures, which may be some distance away from screening checkpoints in the larger airports – a fact commonly cited to explain why technology sharing among agencies does not occur.

Documentation and Auditing Processes

Since strip searches are so rare, there is little excuse not to carry out robust checks to ensure that each search is fully justified and completed appropriately. Staff who opt to conduct a strip search will know that there may be legal ramifications, and so it is in their interest to ensure that any searches are thoroughly documented. In addition to the passenger/guardian consent form, a detailed report should be completed by the screening officer performing the search. This should include details such as why the search was conducted, the time and location, who was present, how the alarm was resolved, and any other details that may be relevant should an investigation be deemed necessary. These reports should be regularly internally audited to complement any external audit procedures required by states.


All too often, news reports emerge of security personnel abusing their power and subjecting passengers to humiliating – and often unnecessary – search procedures. Of course, we cannot account for those disturbed individuals who are simply in the job for the wrong reasons, and there is little we can do to appease those passengers determined to be outraged by everything. But, as outlined above, it seems that so many of these incidents could be avoided by asking oneself a few simple questions:

  • Have I used the least invasive procedure to resolve the alarm?
  • Have I clearly communicated my justifications for a strip search to the passenger?
  • Have I listened to the passenger’s concerns and done all in my power to address them?
  • Have I behaved professionally?
  • Has all relevant paperwork been thoroughly filled out?

If the screening officer can answer ‘yes’ to all of these questions, then we can be fairly confident we’re utilising strip searches appropriately.

“…the officers conducting the search must act with high levels of professionalism at all times, regardless of whether the passenger is wearing Spiderman underwear, a chastity belt, or has a genital piercing…”

Component parts of devices have the potential to be infiltrated through checkpoints on clothing or close to sensitive parts of the body. Some may cause alarms that are dificult to resolve without physical inspection. (Credit: Green Light Ltd.)
Component parts of devices have the potential to be infiltrated through checkpoints on clothing or close to sensitive parts of the body. Some may cause alarms that are dificult to resolve without physical inspection. (Credit: Green Light Ltd.)

Having said that, this article has so far not addressed an issue that seems to have seeped into every aspect of life over the last few months. During the coronavirus pandemic, there has been a global effort to reduce contact between individuals in order to limit the transmission of COVID-19. As the aviation industry begins to recover, we find ourselves questioning how these concerns will impact upon security.

“…if certain areas of the body are not viewable even when naked – e.g. beneath long hair, breasts or folds of fat, or in the intergluteal cleft – it should be the passenger who touches their own body, rather than the screener…”

As the Airports Council International (ACI) stated in its March Advisory Bulletin, the industry must aim to reduce physical contact between staff and passengers via a number of measures, including by significantly reducing our dependence on pat-downs. Could it be that as we skip this measure in our ‘stepwise’ approach to security, we start to see a rise in visual, contact-free strip searches, particularly in regions where the alternative measures cited by ACI – explosive trace detection (ETD) and explosive detection dogs (EDD) – are simply not available? In all likelihood, for practical reasons relating to time, space, manpower and, perhaps most importantly, passenger dignity, the answer is ‘no’.

“…ACI stated, the industry must aim to reduce physical contact between staff and passengers via a number of measures, including by significantly reducing our dependence on pat-downs…”

However, we must not forget that innovation is a hallmark of many of the modern-day terrorist plots. Michael Cardash emphasises continued evolution of the threat by highlighting that, “On Christmas Eve, December 24, 2014, the 13th issue of al-Qaeda in the Arabian Peninsula’s (AQAP) English-language Inspire magazine was released by the al-Malahem Media Foundation, containing a detailed manual on the assembly of a non-metallic IEDs that could be concealed on a person, aimed specifically at infiltrating airline security apparatus and downing an aircraft”.

Cardash refers to a Terrogence incident report in 2016 stating that a discussion was instigated on a pro-Islamic State password-protected forum, Shumukh al-Islam, about explosives detection measures in airports. One user specifically asked, “if an IED containing a chlorate-based main charge with black cumin (Nigella sativa) concealed inside a cotton teddy bear, and an acetone peroxide detonator would be able to pass through security measures in place at airports.” The answers to this question demonstrated detailed understanding of the capabilities of the technologies deployed and, more importantly, how to ensure IEDs could pass through checkpoints undetected.

We can be sure that those intending to perpetrate attacks on the industry are closely observing our response to the current health crisis. Ensuring we do our best to limit infection is important, but the quality of security simply cannot be compromised to achieve that. There must be a system in place to conduct more detailed searches of individuals, and screeners must feel supported in their decisions to escalate cases when the occasion calls for it.

Ally James

Alexandra James is a researcher and trainer for Green Light and the sub-editor of Aviation Security International. She also recently completed a Master’s Degree in Forensic Linguistics at Cardiff University.