So I think it’s important that prospective students are told a little more about course content and so I am going to give you a bit more of an insight to one of the forensic modules we study here at Glamorgan in the second year of the Forensic Biology, Forensic Chemistry, Forensic Science(Good video link under Forensic Evidence) and Police Science courses – “Forensic Evidence.”
One of the topics we cover for practical and in-class assessments is that of ESDA. What’s that I hear you say? I thought the same too when our lecturer mentioned it. ESDA stands for Electrostatic Detection Apparatus and is something that we all touch upon in the first year module: “Criminalistics,” but only very briefly and not in great detail, that is until now.
During the first year ESDA is used to help lift footprints from laminate flooring as part of a practical exercise involving lifting of fingerprints and footwear marks. In the second year ESDA is revisited as part of an assessed piece of work involving documents, worth a small, but helpful and desirable 8% of the module mark.
That’s all very good Jon but what is it? Right well ESDA is a piece of equipment used to reveal indentations on certain questionable documents used in legal cases. Say, for example, a suspect of a murder investigation was having their house searched and that a death threat had been sent to the victim just days earlier (retrieved from the crime scene) this can be examined using ESDA to see if any previous information shows up. This can then be compared with other documents written by the suspect and see if they match. Ok, so this may be a bad example, but the concept is there.
How does it work? The document in questioned is placed on top of the apparatus with a vacuum-type pump ‘fixing’ the sheet upon it. The document is then covered in a ‘cling-film’ type sheet to stop any contamination from the medium used to develop the markings. This allows the document to remain in its original form should it be needed for further analysis elsewhere. Black toner is added to a tin with small beads within it and these are then emptied carefully over the document (at an angle) several times to develop indentations and reveal information from previous, overlaying sheets of paper.
There are certain conditions that need to be met for the development to work, but that is for another time. Overall, this piece of work was rather fun to carry out and as it was done in small groups there was a lot of one-to-one time with the lecturer, which is a great help.
That’s it for this week; next Friday I will go over fingerprinting techniques from first year – awesome!
Until next time!
If you want to check out ESDA a bit more, here are a few useful links with a bit more information:
Forensic Examination Services: