Superglue: The surprising (to me) hero of forensics.

 

Superglue is one of the unusual heroes of Forensic Science. In an episode of the BBC’s Death in Paradise, the detective uses it to develop a some fingermarks from inside a pair of surgical gloves.

Did I just say FINGERMARK rather than fingerprint? Well yes, I think the entire cohort I took my course with learned that lesson on the first semester end of term paper – it was  -½ a point for each time we made that mistake.

To be clear:

FINGERPRINTS are the clear, complete images taken at a police station by a dedicated officer.

FINGERMARKS are the dodgy half imprints left behind at a crime scene.

Superglue or rather Cyanoacrylate fuming is primarily used for non-porous surfaces like that surgical glove mentioned about. And of course, the readiest form of cyanoacrylate is superglue. The method was discovered in the late 1970s by the US army stationed in Japan. The cyanoacrylate reacts with moisture to create a hard coating over the lines in the latent fingerprints, and it prevents the mark from accidentally being rubbed away. If you have a big enough ‘fuming cabinet’ it can hold a lot of items that need processing making it a cost effective volume processor for when a number articles are held as evidence. The fuming process produces a faint white mark that requires an extra stain in order to see the print. The vapour also leaves a white residue on surfaces of the cabinet. The fumes from superglue are noxious but not toxic[i].

So who had the brilliant idea about fingerprints in the first place? Sir William Herschel, a British Administrator in India, used fingerprints in1858 to validate civil contracts. The first use in a criminal investigation was in 1891 by an Argentine police official, Juan Vucetich, who used a fingerprint on a door frame to prove a woman had killed her own sons[ii]. In 1901, Scotland Yard adopted the use of fingerprints in identifying criminals, although the fictional detective Sherlock Holmes used fingerprints to solve crimes in stories published before then[iii].

The main issue with fingerprints is they are often ‘latent’, which means hard to see, and require some form of enhancement. The oldest method of fingerprint analysis is the use of silver nitrate. On exposure to sunlight the white silver nitrate, bound to the Chloride in the latent fingerprint, turns black. However, after about a week details in the fingerprint fade and this makes it difficult to make a long-term fingerprint data base. Which is why, nobody uses this method anymore[iv].

The other main method in use at the moment is Ninhydrin dye. Ninhydrin dye is attracted to ammonia and primary and secondary amines – compounds with nitrogen in them – in the sweat residue of fingerprints. The advantage of ninhydrin is that it can be used to enhance a fingerprint on porous paper, as well as the non-porous surfaces that superglue works on. The porous substance is dipped in ninhydrin dye and left to dry – usually for 48 hours but this can be hurried along by warming, as in the case of this experiment. Once dry, the fingerprint is displayed by a deep purple colour called Ruhemann’s Purple, after the man who first noted the effect in 1910. It is also good for enhancing old fingerprints, but the reagents are expensive. As the ninhydrin remains on the treated surface further prints can develop if it is incorrectly handled[v]. Ninhydrin is toxic and an irritant. If gloves are not worn when handling the ninhydrin coated paper then the holder’s fingers will also turn purple.

There are other methods of developing fingerprints but they tend to be more expensive like gold plating the fingerprint, which is long-lasting but not practical for everyday police work. 

For those of you for whom this is not new information, I had never watched an episode of CSI or other serious cop shows. I walked into the Graduate Fair at the University of Strathclyde expecting to sign up for a Pharmaceutical MSc or other Bioscience. Somehow, I ended up getting talked into Forensic Science. I started that course from cold, 30 years after finishing my BSc (hons) Biochemistry, 20 years after I had to give up laboratory work to care for my Autistic son.

And I loved it.

So to me superglue is marvellous, the cheap and cheerful method of storing fingerprints and fingermarks to create a decent database.  

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[i] Penven, Don. (2015) ‘Developing latent prints with super glue’, Crime Scene Investigator Network. February 27. [Online] available at https://www.crime-scene-investigator.net/cyanoacrylate-fuming-a-mainstay-of-crime-scene-investigation.html (accessed 28/09/2019)

[ii] ‘History of Fingerprints’ (2018) Crime Scene Forensics, LLC, Concord, NC; www.crimescene-forensics.com [Online] available at http://www.crimescene-forensics.com/History_of_Fingerprints.html (accessed 28/09/2019).

[iii]O’Brien, James. (2014) ‘Sherlock Holmes: Pioneer in Forensic Science’, Encyclopædia  Britannica, Inc, March 31 [Online] available at https://www.britannica.com/topic/Sherlock-Holmes-Pioneer-in-Forensic-Science-1976713 (accessed 28/09/2019).

[iv] ‘Chemical detection Techniques’ (2019) Australian police.com [Online] available at https://www.australianpolice.com.au/dactyloscopy/fingerprint-detection-and-enhancement/chemical-detection-techniques/ (accessed28/09/2019).

[v] ‘Ninhydrin – visualizing of fingerprints’ (2019) Eviscan. German eForensics. [Online] available at https://www.eviscan.com/en/glossary/ninhydrin-visualizing-of-fingerprints/ (accessed 28/09/2019)

How Effective Are Pre-Laboratory Videos?

 

How Effective Are Pre-Laboratory Videos?

 

 

Presentation of Poster at MiCER2020 conference.

The Methods in Chemical Education Research held an online conference last year. My MSc supervisor encouraged me to attend the conference and present a poster to show my work. I was lucky enough to have my poster accepted for a presentation slot. These were held on June 11^th 2020 in Zoom breakout rooms – each poster had its own room for 40 minutes. Conference attendees could switch between breakout room.

My poster was to be presented in session A, breakout room 8.

This was the final version of the poster I presented at the conference after taking in the advice from my supervisor Dr Patrick Thomson.

I had a short spiel, which I could keep returning to as people arrived and left the poster breakout room.

“My name is Vanessa Knipe. I’m an MSc Student reading Forensic Science at the University of Strathclyde.  Due to CoV-19 I am unable to do a regular lab project so I have invented this project to fulfil the thesis requirements of the MSc degree programme. As you can see I’m a mature student, due to a career break to care for my Autistic son it has been 22 years since I last worked in STEM, 30 years since I attended University.

“The project grew out of the startling difference in presentation of the subject matter, in fact I found the degree of ‘interactivity’ that modern students expect from their tutors to be very distracting.  In undergraduate practical laboratory sessions, and working in medical labs, we had been required to follow strict standard operating procedures but the MSc practical required interpretation of the instructions. The university provided pre-laboratory activities to help with the interpretation. I felt that the pre-lab videos were the most helpful of those activities and wondered if the other students shared that feeling. Did this feeling show any correlation with improved grades?

“As laboratory-based projects were not possible in 2020, I was allowed to undertake a statistical analysis of the grades of four years of students taking the course culminating in the cohort of which I was a part. In this time one of the practicals had a pre-lab video removed for what were considered good reason, so I could analyse the data of this practical against two controls, one with a video in all four years and the other with no video for all four years.”

As this was a Method in Chemistry Education Research conference, I took them through my intended methods using the simple flow chart shown below.

“Even when I was at University 30 years ago, I loved mathematic and statistics. When I started on this course they introduced me to Excel, which was nothing like the Excel I used to use. I could calculate the standard deviation of over 2000 results in under 2 minutes. I was charmed.

“I was also given permission by university Ethics committee to run a survey of students in my cohort. After evaluating the various survey platforms, they seemed to have similar functionalities, I chose Qualtrics on the basis that the University of Strathclyde already had an account.  This is intended to give me some numerical values which I can compare against the results of my statistical analysis and some written answers to give me a context in which to interpret my results. The written answers will be analysed using the methods of Thematic Analysis made popular by Virginia Braun and Victoria Clark at the University of Auckland.

“I hope to see whether or not the videos have been effective for the teaching of MSc Students, and also to write a script for a new teaching resource for one of the experiments which has no pre-lab video.”

For the actual day I used an outline version to prevent me just reading from a script instead of presenting the poster.

It runs as follows

• ·         I’m an MSc student in Forensic Science
• ·         Due to CoV-19 I am unable to do a regular lab project so I have invented this project to fulfil the thesis requirements of the MSc degree programme.
• ·         It has been 22 years since I worked in STEM
• ·         30 Years since I last attended University
• ·         The difference in presentation of the subject matter in Lectures was startling.
• ·         I found much of the interactivity parts distracting
• ·         The laboratory part of the course required interpretation rather than following strict SOPs
• ·         I felt the pre-lab videos very helpful with that level of interpretation and wondered if other students had the same feeling
• ·         Did this ‘feeling’ about how helpful the pre-lab show any correlation with improved grades
• ·         As I couldn’t do a laboratory-based project I was allowed to undertake statistical analysis of the effectiveness of the videos as my MSc project
• ·         I hope to see whether or not they are effective and to write a script for an new teaching resource for one of the experiments that had no pre-lab video. 

I used this as a basis to run a circular talk which visitors to my breakout room could drop in and out again at the point where I started repeating.

At the end of each cycle I asked if there were any questions.

Two interesting questions were...

Q1 – I’m having trouble engaging my pupils with pre-lab videos, what have you found that helped.

A1 – I suggested that there was a difference between the traditional video that depicted a demonstrator at the front of the lab and the new style of First Person Perspective (FPP) videos using a Go Pro camera. This might help engage reluctant learners if the video was in FPP.

Q2 – As someone trying to do a project in this time, what was the most difficult part of making up a survey?

A2 – I suggested that my research had shown that nine minutes was the ideal length of time for a survey to take and I had difficulty in compressing my questions to fit that ideal time.

Both appeared happy with their answers.

I had an interesting discussion with another person about the usefulness or otherwise of Likert Scale versus sliders in the Qualtrics Survey platform.

 

Eclipse

 On the 20th of March 2015 there was an eclipse that came to about 93% of totality over the house where I used to live in York. 

I had just that Christmas received a new camera from my father so I was eager to try it out. I bought filters and everything.

At 8am the day promised to be absolutely perfect. I sent my son off to Sixth form with two pairs of eclipse specs so that he could share if they let the students out of class to watch. 

Of course the perfection didn't last. 

By 9am the sky had clouded over. And even worse, my special silver filters didn't photograph the sun through clouds. 

Wearing my pair of eclipse specs meant I could see the sun through the clouds that prevented my photography. Oh well, at least I'd see the eclipse, even if I couldn't record it.

That was when I had my bright idea. While the special photography filters didn't work, holding my pair of eclipse specs over the lens gave a sort of red filter that let me photograph the sun through the clouds. 

I achieved a series of shots by using the red filter when the clouds covered the sun and the silver filter when I had a gap. 

This is my favourite one. 

"Well! I've often seen a cat without a grin," thought Alice; "but a grin without a cat! It's the most curious thing I ever saw in all my life!"

-Lewis Carroll from Alice in Wonderland.

The Intelligence Value of Drug Profiling

 

 What was I doing last year? I was at the University of Strathclyde reading for an MSc in Forensic Science. This post was originally a presentation, now adapted for my blog. 

The Intelligence Value of Drug Profiling

Before I signed up to this course I took the MOOC (Massive Open Online Course) on Forensic Science, run by the University of Strathclyde. While it was mostly about a Murder Investigation, the course content took a little side quest into drugs. In my previous work I did Drug Testing for recovering addicts and thought I knew quite a lot about drugs, but the MOOC taught me one new thing: by profiling drugs, that is identifying their component parts like cutting agents and route specific markers, you could link batches of drugs that came from same clandestine lab.

It is my ambition to communicate science to non-scientists, so I’m taking a slightly different angle.

In order to answer the question of the Intelligence Value of Drug Profiling we have to visit the 3 of the 6 Ws which are so important in a police investigation. Why do we need profiling? What are we profiling? And How does profiling work?

So…. Why do we need profiling?

    Detective Lola Cat is hunting for the source of illegal catnip in her town.

Illegal catnip is pouring into the small Scottish town of Dalry. Irresponsible dealers are addicting innocent kittens to the foul drug. Detective Lola Cat is hunting for the source. Juveniles of all kinds are more easily addicted to drugs and Detective Lola Cat is determined track down the clandestine lab or labs responsible for catnip products flooding the market.

Drug Profiling can help track down the source of illicit drugs

What are we profiling?

Drugs come in a variety of forms

Drugs come in many different forms. They can be tablet based or powders. They can be smoked, injected or swallowed. New products come on the market with alarming regularity. Intelligence is needed to find a link between products and dealers in order to shut down the supply.

Here are a sample of recent seizures of catnip-based products. As you can see, starting bottom left and going clockwise, there are the classic leaf-based products, pellets that are smuggled inside cat toys, edible products and the latest release of semi-synthetic catnip in the form of  sprays. This collection is from multiple different seizures and Detective Lola Cat needs to know if there is a link between them. The way to ascertain if there is a link is by drug profiling.

How does profiling work?

 

Drug profiling’ is defined as the extraction of a drug’s chemical and/or physical properties to be used in the application of policies against the illegal use of drugs. - Forensic drug Intelligence: An important tool in law enforcement.  Pierre Esseiva et all.

With drug profiling it is possible to trace a common origin of the product by looking at the added diluents and adulterants. A diluent is a chemically inert product used primarily to bulk out the drug so that more can be sold. Adulterants often have similar properties to the drug but can be obtained more cheaply and easily.

When the test results come back Detective Lola Cat finds these catnip biscuits have been adulterated with tuna. The analysis reports that none of the other products contain tuna. This Intelligence eliminates the biscuits as coming from the same clandestine lab as the rest of the catnip products and directs the course of the cat police investigation. Detective Lola Cat is looking at two or more clandestine producers of catnip.

Am I being a little silly and not taking this assignment seriously?

 

  Drug profiling - image from University of Strathclyde, Centre for Forensic Science, Future Learn open course website.

 

Not entirely. I admit I simplified a very complex subject matter to fit into a five minute presentation. 

This is how drug profiling works. Chemical analysis of a seized drug can show the ratios of drug to impurities. No matter what cutting agent is added, the ratio will remain the same. Additional analysis identifies the cutting agents. Two samples may have different cutting agents but the ratio of impurities in the samples is the same. That tells us that two different dealers could be obtaining their pure product from the same clandestine lab, before cutting agents are added.

The Intelligence value of Drug Profiling is that it gives the police linking information so they can follow the drugs back along the user/dealer network.*

*Keith Borer Forensic Consultant‘s Website. Available at https://keithborer.co.uk/news/drug-profiling-common-source-what-does-it-actually-mean-your-case  

 

 And remember, Detective Lola Cat urges your vigilance in protecting kittens from the dangers of catnip abuse.