Impossible fingerprints

[Simon Bunter]

The below link is to my case study article that has just been published in Fingerprint Whorld.

Link to article: http://www.keithborer.co.uk/news/view-a ... f-evidence

This is a case I worked on recently where the prosecution alleged that prints on a security gate were from the offender trying to force it open. I was able to show (spoiler alert) that the prints were from the defendant having handled the gate during work experience some 10 years earlier. Contrary to the police's specific allegation of the prints being 'consistent with forcing the gate', they were actually virtually impossible to achieve with the gate affixed in place and were fitting with him carrying it before it was erected.

Consequently, not only was it possible to show that the prints were not placed at the time of the offence, the fingerprint evidence did not even demonstrate that the defendant had entered the building where the offence occurred.

[Alan C]

I seem to recall a similar case here over 15 years ago. It was a commercial burglary where a latent was lifted off a cubicle divider wall. It was run through our AFIS and hit on a record from an old drunk-driving arrest. It turned out the suspect had installed the divider, so no charges were filed.

[Simon Bunter]

Hi Alan

I think there are probably more of these types of cases than people think. What was particularly disturbing about this case was that:

-The prosecution persisted with the charge despite the defendant having worked in the metal fabrication workshop all those years ago.
-They persisted with the charge despite me showing that the type of contact was almost impossible to achieve.
-The police officer in charge of the case provided a statement incorrectly detailing how contact could "easily" be achieved. In short, providing 'expert' evidence outside of his area of expertise.

Simon

[Dr. Borracho]

In short, providing 'expert' evidence outside of his area of expertise.

Cops do occasionally extend their testimony beyond their training and experience, as do people from every walk of life.

Especially statisticians.

[Simon Bunter]

You're right, Police Officers do occasionally give evidence outside their training and experience. My point is that they should not.

I'm not sure what statisticians have to do with this case.