Detectives are hunting a yob who jumped on a police car smashing the windscreen on Saturday night (January 22).
Officers revealed the incident happened at around 9pm just after a group of people were seen in the University of Northampton site.
One ran up the bonnet of the police vehicle, parked in Village Walk, damaging the windscreen in the process.
Police have issued an image taken from security cameras showing a man they want to speak to in connection with the incident.
UoN Policing Sergeant, Lorna Clarke, said: “The person who did this is not thought to be a student as it was someone who came onto the site from New South Bridge Road.
“Damaging a police vehicle takes a much-needed resource out of action, wasting public money and time as a result.
"We are asking for the man in the image or anyone who recognises him to call Northamptonshire Police on 101 using incident number 22000043252."