Teacher Sarah Cardew, Jonathan Friesem, 10, ten-year-old Alex Humphrey, Flora Leith-Ross, 11, Ian Pepper.
CRIME scene investigators called into Yarm Preparatory School to solve the mystery surrounding two different footprints.
Pupils enjoyed a special assembly with the principal lecturer in policing at Teesside University, Ian Pepper.
The role of the CSI was explained and pupils had the chance to dress up in an investigators outfit or have their footprint taken.
Alex Humphrey, 10, said: "It was great dressing up as a CSI even though it was hot, I would like to be one as it sounds very interesting."
Headteacher Gillian Taylor added: "The children had a fantastic time and the assembly not only helped prepare them for their CSI day next week but also highlighted the importance and adaptability of science."
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