CSI Cobham

Posted: 18th February 2023

On Saturday 4th February, we welcomed students from a range of local primary schools, who, with help from our own students, used a range of tools and experiments drawn from forensic science to track down the villain in the murder mystery: Who Murdered the Deputy Head?

A horrific crime took place on Friday night and Mrs Carney was found murdered!

At the crime scene, there was a suspicious white powder and several potential murder weapons, including a saucepan, a tree branch and a chair.

Students were given evidence bags with the samples found at the crime scene to analyse. They linked these to information about the suspects.

Students were also provided with a list of suspects and possible motives, then analysed evidence bags with samples found at the crime scene to figure out the culprit/s.

The victim

Mrs Carney: our Deputy Headteacher.

She is jointly responsible for running the school and must make many difficult decisions every day. Mrs Carney has to be aware of what the whole school community need but it isn’t always what they want. This means that there are a lot of tough conversations with staff which can lead to upset and resentment.

The suspects

Mr Hearn: part of our Maintenance team.

His job takes him all around the school site. In the dungeons, up in the towers, in the classrooms, and even on the roofs. There isn’t anywhere in the school that he doesn’t know.

He always carries a selection of tools with him as he must be prepared for all eventualities.

Recently he asked Mrs Carney for some equipment to be ordered but she said that as he was forever leaving pens and tools around the school she wasn’t prepared to buy anymore.

Mr Malcolmson: our Film Studies teacher.

He really enjoys his job. He gets to watch lots of different types of films and is very enthusiastic about his subject.

His lunchtime Film Club is popular with students, but Mrs Carney was unhappy when she found him lounging back in his chair eating sherbet lemons forgetting that he wasn’t at the cinema. There was sherbet all over him and on his carpet

Mrs Hearn: works in Laundry.

She works hard keeping bedding from the boarding houses and sick bay, uniform, napkins and tablecloths used at functions, sports kit and many other items clean and tidy.

She prides herself on keeping the laundry room looking nice but there was a problem with one of the washing machines which led to a big spill of washing powder.

Extra work clearing it all up for Mrs Hearn who doesn’t think Mrs Carney will ever agree to buy a new washing machine to avoid this happening again.

Mrs Adams: one of our gardeners.

She is always complaining about how chalky the soil is which makes it too alkali for many plants to grow.

She has become increasingly frustrated that she is not allowed to buy something to help to neutralise the soil around some of the plants to improve the situation.

Mr Kirkaldy: our Chemistry teacher.

His lessons are always popular because the students find them interesting especially if it involves fire, explosions, bubbling and exciting reactions.

He has access to a lot of chemicals and recently taught the topic Acids and Alkalis to his students.

Mrs Carney is always nervous when she goes into the laboratories as they feel like places of danger, although she knows that they are run safely.

Mr Meaner: our Head Chef.

He is always busy in the kitchen preparing food, cooking and baking.

His meals are always tasty, and students and staff comment on how varied his menus are.

However, recently he was told by another member of staff that she overheard Mrs Carney complaining that his food was too salty!


Each suspect came under intense scrutiny and all the evidence was carefully analysed. But the question remains… Who murdered the Deputy Head?