Forensic Science

Forensic scientists help the police to solve crimes and help lawyers in court to explain what might have happened when someone is accused of breaking the law. Their findings are presented to the jury, members of the public, who decide if the person accused committed the crime or not.

Forensic scientists can use physics, chemistry, biology and maths.

Today, you will meet two researchers from the Leverhulme Research Centre for Forensic Science, Holly Fleming and Hilary Arsenault. Holly Fleming uses different colours of light to help see some types of evidence that would otherwise be hard to see. Hilary works as a forensic biologist and works mostly with DNA. They have created two fun hands-on activities related to their jobs.

Invisible Inks: secret message writing and revealing

In forensic science, some types of evidence are hard to see. Scientists can use a combination of dyes and coloured lights to help them. The dyes and lights can detect certain materials and make others more visible, such as fingerprints or blood.

In the invisible ink activity, you will write a secret message on paper. It will be invisible. You will then reveal the message by using a secret ingredient!

DNA transfer and persistence (using extracted DNA)

When you touch an object, you leave DNA behind. For example, when you touch your pencil you leave some of your DNA on that pencil. In her job, Hilary tries to understand how DNA gets to, and reacts with, the surface of an item. It is her job to understand how the DNA got onto the pencil and when it was put there.

In this activity you get to see DNA! Single strands of DNA are so small that your eyes cannot see them. This simple DNA extraction activity will let you see DNA by taking a bunch of single strands and grouping them together. This group of DNA will be big enough for you to see!

Also see the extraction video saliva (Activity 2) from Forensic Week from last year.

If you have enjoyed these activities, you can take on the case of the stolen tiara and try out more forensic experiments to try and catch the culprit.