BREAKING NEWS: There has been a crime at the Fun Science HQ. Chemical Cress has discovered that all of her delicious digestive cookies for the Big Experiment have been eaten!
Clearly, some forensic investigation (detective talk for “collecting clues”) is required. This is the perfect time to whip out our Fantastic Fingerprints experiment.
You will need:
- Two pieces of paper (preferably one scrap, to help the environment)
- Some sellotape
- A pencil
Collect your fingerprints:
1) Use your scrap paper to draw a filled square.
2) Press the finger of your suspect into the square.
This process moves the graphite molecules from the paper onto the ridges and grooves of your finger.
3) Push that finger into a section of sellotape.
4) Press that sellotape section onto your clean piece of paper, and label it. This is your fingerprint!
Now you have a record of a fingerprint. Do this for all of your suspects, and you can compare this to fingerprints you collect at the scene of the crime to discover the culprit!
Fingerprints are essentially unique to every human being. Investigators, such as police officers or detectives, collect them. This is because, by matching collected fingerprints to ones in a database, you easily identify someone who has handled an object or touched a surface.
Humans have recorded fingerprints since ancient times. That said, Historians think people probably didn’t realise that everyone had unique fingertips until Victorian times; In 1840, a Doctor wrote to the police, suggesting checking for fingerprints to investigate a murder.
In The Adventure of the Norwood Builder, a Sherlock Holmes story released in 1903, a fingerprint is the key piece of evidence that helps the detctive solve a crime. Fingerprints have been used in crime stories and real life forensic investigations ever since.