A woman and her mother were assaulted by a man with a Batman tattoo on his hand who then caused extensive damage to the driver's car.
On Sunday, March 17, between 2pm and 2.30pm, the woman parked her car, a black Peugeot 106, in the Little Park Street area.
The man then approached the car before assaulting the woman and her mother and then he caused extensive damage to the vehicle by kicking and jumping on it.
A Northamptonshire Police spokeswoman said: "The man is described as a white man, aged about 26, about 5ft 8in, of average build with short dark brown hair and a beard.
"He was wearing blue jeans, blue trainers, a grey Armani jacket and black beanie hat and was carrying a black rucksack. He also had a Batman tattoo on his right hand."
Witnesses, or anyone with information, are asked to call Northamptonshire Police on 101. Alternatively, they can call Crimestoppers anonymously on 0800 555111.