Forensics is the science used to help solve crimes. This could be finger print indentification, analysing samples, looking at hair samples under a microscope to find DNA and much more!
In your kit you should have:
Crime scene tape
Suspect sample 1
Suspect sample 2
You will need:
Clear sticky tape
Look at your finger, can you see your fingerprint? Did you know that your fingerprint is completely unique? No one else has a fingerprint exactly the same as yours!
Take your magnifying glass and look even closer at your finger. Does it look like any of these –
Check your other fingers, are they the same?
Just because people can have the same type of fingerprint, no two fingerprints will ever be extactly the same, even in identical twins! If there is a fingerprint at a crime scene then it can be a really good way for scientists to identify who was there.
Taking a fingerprint
Now-a-days forensic scientists use computer scanners to take records of people fingerprints. But before this they would print them onto ink. You are going to try and take your own fingerprints, or someone in your household.
Colour in a section of your scrap paper using a pencil, big enough to fit your fingerprint on.
Press your finger onto the paper, you should find the pencil transfers to your finger. If not, go over the section of paper with the pencil again.
Take some clear sticky tape and push your finger onto the sticky side.
You should see that your fingerprint is visible on the tape!
Stick the tape onto some paper to keep a record of your finger print. You could write which finger it is from.
Why not try doing all of your fingerprints and comparing them?
One key part of forensic science is analysing samples. This means experimenting on samples to find out what they are and where they might have come from.
For this next experiment you are going to try and narrow down 2 suspects from some samples found on their clothes! Detectives are looking for a substance that fizzes when it is put in water.
Open sample 1 and pour in water, enough to cover the sample.
Do the same with sample 2.
Do either of them fizz?
If you had a sample that fizzed, this helps to narrow down the suspects in the case! Of course, forensic scientists would need to do lots of other tests, and work with detectives to be sure.
Another thing detectives look for is splatters, this might be from blood, sweat, or even a milkshake that someone was carrying! The size of the drops and the pattern formed by the liquid can tell us a lot about what happened at a crime scene. You are going to test and see if splatters of liquid look different when they are dropped from different heights.
*You might want to do this outside*
Take a cup of water and your tape measure.
Hold the cup 1 meter above the ground – use your tape measure to make sure you are accurate.
Spill some of the water onto the ground.
Use your tape measure to measure the width of your splatter. This is more accurate than looking.
Repeat, but this time start at 2 meters high.
Is the splatter different?
Do this at as many heights as you like, and compare your results from the different heights!
Do the splatters look similar?
You should notice that the diameter (how wide it is) of the splatter shows how far away the liquid was from the ground when it was dropped.