One of my recent courses (Future Learn) was “An introduction to forensic science”. This was quite interesting and there were some things that were totally new to me about DNA and what is stored on the police databases. Not sure I totally understood it and fairly sure that I won’t remember it in detail, but interesting, never-the-less.
One of the weeks was about fingerprints and they told us a way to take your own. You rub the side of a pencil on paper, roll your finger across the pencil mark, roll your finger across sellotape and stick the sellotape to paper to examine the marks. I did try, but all I got was a smudge! Mind you, looking at my fingers the ridges are not very pronounced. Someone commented that ones prints do get less clear with age – so now is the time to do the crime! (So long as you don’t leave any DNA around.)
The other thing to try was foot-marks or shoe marks – not footprints which come from bare feet. To do this you take your shoes (old ones for preference) and paint olive oil on the bottom with a paint brush and then press the shoe onto paper. I used vegetable oil (cheaper) and the first attempt was not too successful.
As you can see this was very smudgy and didn’t show much! I wiped the oil off and tried again but put much less oil on the shoes.
These were much more of a success. The “class marks” – those that are standard for all shoes of the same type – were fairly clear. The outer ones are one pair and the inner one was one of a different pair. The individual marks just come out as a smudge, even the cut was not obvious, but it is clear that there are wear marks, which might or might not be fairly individual. NB Wear new shoes when committing your crime!
It was interesting to learn about some of the techniques used in forensic science, including those I have mentioned and tool marks and ballistics, including “threading” to see where blood splash marks came from so learning where the person was when the bullet (or knife?) hit the person. The initial scene of crime officer would need to be really good at observation and remembering what was there. Anything not noticed initially is lost.
So? Quite amusing to try the techniques, but I am not sure I had better commit that crime or expect to solve one either!