Celestine's CSI Journal 2012: Second CSI Lesson- Lab work! :)

For this lesson, we got to do some hands-on activities in the lab. We were really excited to get started but before doing any hands-on activities, we had to watch some videos on YouTube to allow us to gain some knowledge of what we will be doing (There's no point doing something when you don't know what the purpose of doing that thing is right...?).

The links to the videos were on the website for CSI lessons' resources and we learnt various methods of identifying, revealing and showing fingerprints on surfaces where fingerprints are printed but cannot be seen with the naked eye. In our previous lesson, we learnt the most basic way of obtaining our fingerprint, which is to put ink on our fingers and print it on paper.

For this lesson, we learnt different methods of revealing fingerprints that cannot be seen with the naked eye. The methods are: iodine fuming, super glue fumes and dusting powder.

Iodine fuming- it is a way to develop prints on porous and non-porous surfaces such as paper, index cards, magazines and cardboard. We were given a strip of paper and all of made our fingers oily by using the oil on our skin (haha gross). Then, the strip of paper is placed into a container with solid iodine. The sublimation of iodine in the closed container will cause iodine vapors to concentrate, then be absorbed by the oil and sweat left behind my human skin. This print is temporary and will be visible as orange/ brown outline. We then cut out our own prints on the strip of paper and stuck it to our worksheet. All the bench members' fingerprints are then inked on that page and labelled as suspects. The fingerprints are then matched to the piece of paper with the temporary print.

Dusting powder- it is way of detecting latent prints. A variety of powders are used in dusting for prints and the powder we used for this lesson is lead powder. This lead powder is obtained by crushing the lead of the pencil using a motar. Then, we made our fingers oily using the oil on our faces and imprinted our fingers on a strip of paper. We then used a brush to brush the lead powder and brushed over the strip of paper to reveal the fingerprints. Next, scotchtape is stuck onto the strip of paper and the fingerprint is transferred onto the scotch tape. Following that, we stuck the scotchtape on a black background in our worksheet.

Superglue fumes- Superglue fuming is a chemical process to reveal latent fingerprints on non-porous items like bottles, firearms, knives, etc. It is by heating superglue, which releases gaseous vapours that adhere to the oily residue of the fingerprint. Firstly, we oiled our fingers and imprinted our fingerprints on a clear piece of plastic. Then we sent it for superglue fuming. Upon development, the fingerprint ridges will appear a white chalky colour. We then each cut out our fingerprint from the clear piece of plastic, and stuck it on a black background in our worksheet.

I think this lesson has been very beneficial as it has brought us up to another level of experimenting and CSI because we get to do hands-on activities. It has built up my knowledge about fingerprinting and I feel like i want to know more about fingerprinting. This is much better than just reading up on notes on fingerprinting.

PHOTOS! :D