TSA Agents Amanda Zug, Shawn Knaub and Kendall Bradley provide a teachable moment in cross-contamination and the need to adhere to contamination protocol

TSA Agents Amanda Zug, Supervisor Shawn Knaub and Manager Kendall Bradley provide a teachable moment in cross-contamination and the need to adhere to contamination protocol

Yours truly being subjected to an enhanced pat down due an invalid IonScan result

I begin this post with a declaration and acknowledgment upfront. I am a Trusted Traveler. I went through the application, background check, and less to obtain my Global Entry ID. I have said publicly and I continue to do so now, that I enjoy being a Transportation Safety Administration (TSA) pre-check customer. It is a good program. While some people decry that the TSA is simply theatrics, an over bloated and ever expanding monster bureaucracy whose results do little to stop, halt or deter those who are determined to do harm while traveling, I am not one of those folks. As a general proposition, I find the people to be working at TSA to be well intentioned and truly believe in their heart of hearts that they are doing the right thing to keep us all safe.

However, on Wednesday December 17, 2014 at the Harrisburg International Airport (MDT), I personally encountered an alarming incident. I am trying my best to put aside the personal feelings I have over the way this incident went down to instead provide a teachable moment. This incident, which is on video that I captured, provides for a teachable moment for those who follow this blog and enjoy applied forensic science.

Also as a declaration, I have taught (and still teach) at Axion Labs and the American Chemical Society (ACS) about the Smith’s Detection IonScan devices (both the 400 and the 500DT) and Ion Mobility Spectroscopy (IMS), which is the underlying scientific principle upon which this device operates. I have a pending peer review article on its validity (or lack thereof) when it comes to cocaine detection as currently deployed by the Northeast Counterdrug Training Center (NCTC) and the Counterdrug Joint Task Force (CJTF) in Pennsylvania. I have litigated against this device and those operating it. As a result, District Attorneys Offices have refused to offer the results of the device into evidence and one judge did not allow its results into evidence in a particular case for issues including lack of specificity, lack of traceability, lack of the adherence to the 5 Q’s, lack of a validation study, lack of a validated protocol, and lack of adherence to Instructions (Standard Operating Procedures). I have extensively litigated Right to Know (Pennsylvania’s form of FOIA) claims to get a tremendous amounts of information on the device, its operation and its training of its operators. I have received affidavits attendant to the device, its application, and training. I have received and reviewed numerous government expert reports on the device. I have a copy of the Smith’s Detection Ion Scan Operational Manual (both the 400 and the 500). I have tried to receive operator training, but have been denied. I am about as familiar with this device as any scientist can be.

This Incident:

The People Involved

  • Justin J. McShane, JD, F-AIC: me, traveler and citizen
  • Alex Duffie: traveler and citizen. I did not know Alex before the TSA checkpoint.
  • Amanda Stanton Zug: TSA Screening Agent
  • Shawn Knaub: TSA Supervising Screening Agent
  • Bradley Kendall: TSA Manager

The Location

  • Harrisburg International Airport (MDT) Middletwon, PA

The Facts:
It all began with my travel plans on December 17, 2014 to go to Chicago ORD via MDT on a carrier. I was traveling with my fiancé. It was among the first flights out in the morning at MDT. As is the case at MDT with the first flights out in the morning, MDT is much busier than normal. Normally, when one comes up to TSA at MDT there is not more than a 4-person line. It is pleasant. As I fly a lot, some of the TSA know my face. I have always found them to be professional.

This morning (12-17-2014) when I came to MDT and to the TSA checkpoint, there was a line (but significantly less than any other airport I have encountered). They appeared to be appropriately staffed.

I was granted TSA pre-check. Unlike other TSA pre-check facilities, MDT has a partial pre-check program whereby the person subject to screening does not have to go through the Millimeter Wave Scanner (see our post on the limitations on the use of Backscatter technology), but instead a metal detector. At this location, a TSA pre-check person still has to completely remove his or her laptop and place it in a bin for the x-ray machine (traditional x-ray, not backscatter). I did so efficiently and with no complaint.

I went through the metal detector. My bag made it through. So did my coat and boots (the boots always set off the metal detector). My laptop (along with some other people’s items) was randomly chosen for enhanced screening.

A young gentleman (after this was all over, I asked for his name to document all of this, he was happy to provide it) who I did not know and who was separately traveling arrived to MDT TSA checkpoint two people ahead of me in the enhanced security area. He decided to bring along 2 bottles of eye solution/contact lens solution in his carry-on. One and been previously opened by the passenger. The other was in its completely sealed box with its tamper evident seal on the cap. As they were declared and as they were separately placed in a bin they were permitted per current TSA guidelines. However, as it liquid it was subjected to an enhanced screening check for volatile organic compounds (VOCs).

An example of the boxed and tamper evident seal of Alex Duffie’s eye/contact lens cleaner (Item#2)

As I am interested in applied analytical/forensic chemistry, and as I was two behind him and awaiting the release of my laptop, I watched the examination of Alex’s two items. The items were presumably placed in the bin by Alex. Alex’s liquid is identified at the x-ray and placed with the other items for random or enhanced screening. They were physically moved from that line of enhanced item check line by a lady screening agent whose name I did not get (definitely not Amanda Stanton Zug).

If you have ever been selected for random additional screening or have carried liquids, you know that the examination is conducted in the same area, which is a steel desk.

This unidentified lady TSA agent employed the “vapor phase test strips” on Alex’s two liquid items. They do so using a reagent after holding the testing strip above the liquid to capture presumed headspace (yet unspecific as to source obviously) above the screened liquid.

First for testing was the opened box of solution. I watched in detail as it was deployed. The reagent was applied. No color change. It was released. They asked him to open the still boxed and unopened box including moving the tamper evident seal. He complied with the request. The headspace VOC analysis using the vapor phase test strip was conducted on this box. The reagent was applied and it turned blue (it was announced as a “hit for explosives” by the unidentified lady TSA agent which I suppose she meant that it was presumptive screening positive for explosives). Alex looked confused. The unidentified lady TSA agent performed another test. It too turned blue. Perhaps sensing the confusion and alarm of some, the unidentified lady agent looked at the ingredients and noted out loud that it had hydrogen peroxide which she stated was a known false positive creating agent. [Blogger’s note: The unidentified lady TSA agent kind of right in the context of the application, but technically scientifically, it is not a false positive. The strip used is actually selective for any form of peroxide. Hydrogen peroxide has been used for creating organic peroxide based explosives, such as acetone peroxide. So that is the issue and perhaps why this particular reagent strip is used.] Alex was told that he had to have a pat down. Before he was removed to the separate pat down area, Alex was asked/ordered to remove everything from his pockets. He promptly did so putting everything on the testing desk where the opened Item#2 remained with its VOCs going everywhere in the immediate area. Someone picked up Item#2 to conduct a Smith’s Detection Ion Scan (in TSA parlance they call it an ETD or Explosives Trace Detection test). Not surprisingly to anyone who understands and knows IMS technology that the Smith’s Detection Unit is based upon or the actual 400/500 device, the bottle also alarmed as it is not sufficiently selective to discern H2O2 (hydrogen peroxide) from HMTD (peroxide based explosive), and TATP (peroxide based explosive).

According to Smith’s Detection (formally Berringer) literature, this is what the device detects:

Ion Scan 500

According to the published evaluation literature, here is the detection limits for various compounds:

Explosives mode

According to the patent (US Patent US20080101995 A1), we find this:

Table 1

Further in the art we see this very clear declaration of limitation on the device:

false positive

It is clear that this device is not sufficiently specific to resolve between H2O2, which is allowed on planes, and peroxide based explosives. It is selective for peroxides only.

Next to enter the picture was TSA screening Agent Amanda Stanton Zug. Prior to the announcement of the “hit for explosives” Amanda Stanton Zug was not in the enhanced screening area. She was with the traditional x-ray. As she approached the enhanced screening area, she approached with the bin and the laptop of the person who was immediately in front of me in her hands. She took the IonScan swab running it over the computer. That person’s computer was not proximate to the still open H2O2 bottle. The sampling was performed in a different location,  removed from the proximate area of the open H2O2. She clamped the sampling wand of the 500DT with this person’s sample. That person’s IonScan ample did not alarm. Her computer was released.

The sampling wand of the Smith’s Detection IonScan 500DT

Next Ms. Zug returned to the traditional x-ray area to retrieve my bin that held my laptop. She placed the bin and my computer on the steel desktop where the already opened and recently VOC emitting Item #2 was or had only shortly been removed. She did not clean the steel table after Item #2 was there. She did not run a blank after the alarm. Of course, a non-alarm sample test is not a blank. Without changing gloves, without cleaning the sampling site or doing anything to determine residual VOCs present from Item #2, she wiped down my laptop. She inserted it in the wand. Not surprisingly it alarmed.

Ms. Zug announced a hit for explosives. A supervisor was summoned for a pat down. I immediately protested. I asked for a re-scan, but only after the manufacturer’s contamination protocol was followed. I asked what it was an alarm for. I was told that they could not tell me. They then removed all items from the steel desk including the offending Item #2 and sprayed it down.

Then entered Supervisor Shawn Knaub who was previously present in the area. This is when the video begins documenting the events up to the enhanced pat down.

There are many issues to consider in this video:

  1. Amanda Zug announces: “I am not ETD. I am only AIT.” The ETD is explained above. AIT is an acronym used by the TSA for a job description known as “Advanced Imaging Technology” which is the millimeter backscatter operator. By implication of her declaration, it can be deduced that she is not certified on the ETD (the IMS based IonScan device). As any scientist knows (and also according to good old fashioned common sense) a valid result can only come about on a stable instrument, using a validated method that is adhered to, using relevant traceable standards, and by an operator who is trained appropriately on the device. Manager Shawn Knaub should have known that his supervisee was not ETD trained. Supervisor Shawn Knaub should have known the moment that she made this declaration and properly refused to do the additional screening that he did not have a valid and reliable alarm from her analysis and should have realized that his analysis (the no alarm test conducted after the contamination protocol was performed) was the reliable and valid result. This should have halted the invasive search and pat down. It should have been resolved with a simple apology. [At the time I did not know what the acronyms ETD and AIT stood for.]
  2. Supervisor Shawn Knaub checking that the verific was in order. I appreciate that. Not allowing me to evaluate it is not. His not examining the full plasmagram is not appropriate. FOIA will tell us if there was in deed a verific valid for that day with a preserved plasmagram.verificpen
    An example Verific sample report
    An example Verific sample report page 2

    An example Verific Plasmagram
  3. Amanda Zug agrees that she did not clean the testing site after the initial and subsequent alarms from Item #2, prior to testing my device. This is against the manufacturer’s protocol.
  4. The swab holder was not cleaned with alcohol. The Velcro pad was not replaced. No blank was performed after an alarm was run. No “Cleardown” was performed as required by the manufacturer. A blank is never another sample. This is against the manufacturer’s protocol.
    Smith’s Detection IonScan Operational Manual

    Smith’s Detection IonScan Operational Manual
  5. No blank was run between samples. Again an unknown can never be a blank. This is against the manufacturer’s protocol.sampleanalysis
  6. As a matter of my opinion (and I suspect a lot of citizens), Supervisor Shawn Knaub asking me “Is this [being respectful, recording the TSA, and simply asking questions] part of your protocol? Is this part of the protocol for your company?” was inappropriate and bordering disrespectful.
  7. The claim that the screening protocol is not accessible to those who are subject to enhanced and very personal searches is unacceptable. While I appreciate that there is a balance between security and public information, I openly wonder if it is indeed part of their published protocol (if one exists):
  • to not control the site of examination and where samples are to be tested,
  • after an alarm happens to not cleanse the site,
  • after an alarm happens to not run a blank,
  • after an alarm happens to not seek a background reading of the area to make sure there is no lingering contamination,
  • after an alarm happens to not change gloves of the operators or those who were in the site of examination,
  • to allow untrained and not certified operators to run devices,
  • to totally disregard a no-alarm result after the contamination protocol is followed from someone who is in fact presumptively a certified operator,
  • to credit an invalid result over two valid results, and
  • subject a citizen to non-scientifically derived conclusions that are consistent with those trying to harm others and conduct a totally evasive search of all belongings and of my most intimate areas (but I guess if it is with the back of the hand).

I edited the video to not include the humiliating and very evasive enhanced pat down that I had to endure because no one either knows or follows the manufacturer’s protocol. I will keep that video for my own. I may publish it later. I may not.

After the pat down I was given an expired personal property/personal injury from Manager Bradley Kendall:

Personal Injury-Property Loss Form

Note that it reads that it expired 11/30/2011.

Expiration notice

Later I learned that Alex’s offending Item #2 was released to him. He got to his destination. I did as well.


On balance, I openly wonder about the technical qualifications of Ms. Zug when she writes on her Facebook:

Amanda Zug

Zug status update

On balance, given his comments to me and given the below Facebook post, I wonder if Supervisor Shawn Knaub has the sufficient lack of bias needed to be in his position:

Supervisor Shawn Knaub
Supervisor Steven Knaub
Knab post
He is entitled to his own opinion and freedom of expression


Here is what I have sent TSA:

• A completed SF-95 claim that was faxed
• A preservation letter for the ESI and data for the incident
• A FIOA request for:
⁃ the security screening protocol in place on that day,
⁃ the verific data for that day
⁃ the ESI data for the device used
⁃ time cards or their functional equivalent for all TSA employees present on that day
⁃ the video of the screening area for that time
⁃ the training certificates for the Smith’s Detection IonScan device for Amanda Zug
⁃ all forms of training certificates for Amanda Zug
⁃ the training certificates for the Smith’s Detection IonScan device for Steven Knaub
⁃ all forms of training certificates for Steven Knaub


My Root cause analysis:

Is this the manufacturer’s fault? No.

Is it the instrument’s fault? No.

Is it TSA’s fault? Perhaps. Better education is clearly needed. Better safeguards need to be put in place to only allow people who are certified on an instrument to operate the instrument and have the results justify an enhanced pat down.

Is it Amanda Zug’s fault? Yes. She should not be operating equipment that she has not been certified on. She knowingly did so. This is wrong.

Is it Supervisor Knaub’s fault? Yes. This is a classic failure to supervise. There appears to be little monitoring of people and what they are or are not qualified to do. There also appears to be a lax culture where co-workers allowed Zug to operate an instrument when she should not. He should have known the qualifications of his supervisees. He should have immediately realized by Zug says “I’m not ETD. I’m only AIT” that he had an invalid alarm generated by an untrained operator. Further, he was present when I got her to confirm that she did not spray down the area after the other alarm and followed none of the contamination protocols. This all coupled with his negative result after the contamination protocol was followed should have resulted in an apology to me for the inconvenience and a discharge from further screening.

Is it Manager Kendall‘s fault? Yes. Although he showed up to the seen after Zug made all of her admissions, he should have pressed his supervisees to verify what the recording and what their own admissions mean. He should not have given me an expired and not topical complaint form.

Who’s fault it isn’t? Mine and other law abiding citizens like me across this country.

My conclusion of the matter

While some people will just simply think to themselves “Jeez Justin just suck it up. Better safe than sorry.” I cannot. I will not. I was personally touched in a manner that I did not want, was not justified and was based upon a falsehood.

Maybe some simpletons will call me unpatriotic. But the security of us all requires diligence and valid testing. Understanding limitations and what results means will not simply result in greater efficiency with fewer false positives but also greater safety through lower rates of potentially calamitous false negatives.

A TSA agents job has to be tough. It has to be filled with stress. I could not imagine what it would be like if someone get through their screening area with a weapon or explosive device and it harmed others. That must be a tough reality of possibility to carry day in and day out. If you couple that with people who are over-stressed and in a hurry to get to their destination, it is perhaps a formula for mistakes. Mistakes do happen. Multiple and repeated mistakes and known errors cannot be simply dismissed or glossed over when it comes to transportation security.

Perhaps what alarms me most as a citizen is the lack of proper protocol awareness (or perhaps they are aware and just did not adhere). The manufacturers continue to make these devices so dangerously simplified so that fast is better than valid. False positives happen all the time. The goal should not be “IMS… so simple even a caveman can do it” but instead make sure

It is hoped that this blog will inspire Ms. Zug and Mr. Knaub to obtain better training and seek to better understand the meaning of the results that they get. It is one thing to have a readable result. It is a whole other thing to have a valid result.


Also, I wanted to be fair. I wanted to provide all 3 TSA agents (Knaub, Zug and Kendall) an opportunity for fair reply and/or a confession of error. I published this post as private requiring a password (meaning not linked to the blog, and not publicly searchable from search engines or through the search feature of the blog) but nevertheless once the url is provided they could see and read the entire post (including this end note). Here is what I wrote each of them on their FaceBook.

Dear (insert name),

My name is Justin McShane. I am the citizen that you encountered this morning (12/17/2014) at about 0520 to 0615 hours. I have published a blog post and published the video that I took. I encourage you to view it. It can be discovered only by people with the url. The url is http://wp.me/p5spZl-2J3. The password is “TSA.” I published this post as private (meaning not linked to the blog, and not publicly searchable from search engines or through the search feature of the blog) but nevertheless once the url is provided you can see and read the entire post as it will appear. In the post it catalogs errors that occurred this day, the manufacturer information and documentation as to the errors, and a root cause analysis. I want to be fair. I hold no ill will. I think this case study provides for a rich teachable moment for many. Unfortunately, it was at my expense. I am happy to publish any written response or any information that you care to share with me and my readers. I will not edit your comments. I think it is reasonable to put a 48 hour limit to any fair reply or confession of error. Therefore, this post will publish with or without your comments on December 19. I look forward to receiving your reply. Thank you. Justin McShane

Facebook Message sent to Steven Knaub offering an opportunity to reply prior to publication
Facebook Message sent to Amanda Zug offering an opportunity to reply prior to publication

Blog update 12/19: There has been no reply. Therefore the blog has been published.

3 Responses to “TSA Agents Amanda Zug, Shawn Knaub and Kendall Bradley provide a teachable moment in cross-contamination and the need to adhere to contamination protocol”

  • 1. That sort of racist stuff as on Knaub’s Facebook page is far worse than the indignity he doled out. It’s not unpatriotic to out a racist, and particularly someone who screens people who are undoubtedly and publicly Muslim, this is worrisome. Please include that in your complaint; that language like what he posts is intolerable for a supervisor in a Federal agency.

    1.1 not surprising that the machinery and its operators are all faulty to an extreme and need to be called out.

    2. Funniest story of the season otherwise.

  • Attorney McShane- this was an extremely interesting and informative article, thank you for sharing. While I agree that someone working in the capacity of a TSA screener/supervisor should (in an ideal world) be bias free, we know that is not likely possible. However, I’m not sure his comments demonstrate actual bias, except perhaps to those intent on causing Americans harm. If I had to draw an analogy, it would be similar to a law enforcement officer stating that criminals should be caught. In any event, I disagree with the previous comment that it was “racist.” In fact Islam isn’t a race, it’s a religion.

  • Justin, I loved the article. You went into far more detail that I did to describe almost exactly the same incident, but over 10 years ago at Reagan National Airport. Like you I carefully observed everything they were doing when I got pulled out of line, then eventually they got to my laptop…and the wand wasn’t cleaned, table not sprayed, and alarm went off. I asked what explosive, they wouldn’t tell me…almost same dialog with multiple TSA agents, then the supervisor, then another one. I explained the deficiencies in their samples (same ones as you! I should not that I was an Executive Consultant with IBM at the time (in a suit, looking IBMish) and my areas of expertise involve computer system measurement and testing, where rules, protocols, and processes are well-defined and deviations are analyzed and corrected). I remember writing up some complaint as well. But, my points about contamination of samples, “sloppy” (can’t remember the word I used) procedures or incorrect procedures implying they were too cheap to use new, uncontaminated cloth, etc.)…was as professional as could be….after 20 or more minutes of explaining, retesting on different machines, changing procedures, I showed them the insides of the computer, showed that I can use it since it was a functional laptop, etc. One supervisor gave up and said “You can go Sir.” I asked what’s going to change, how were they going to make sure this doesn’t happen again, etc. Hmmmm, I guess nothing changed anywhere. The supervisor just kept saying, “You can go Sir”….then, I thanked my lucky “stars” and went on to my flight. I did have one or two more incidents like that around the country and didn’t go through the whole effort of trying to educate them, said nothing, and got through. A few years after that I saw a man start to have the same experience arguing with the TSA people when the wand detected explosives…I shook my head and told him: “Its not worth your time…they don’t listen”. Great story, Justin…I hope you succeed where I failed in making an important change in TSA procedures……..Sincerely, Retired traveler.

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