A man exposed himself to a group of children in Northampton then chased them through an underpass.
The man, who was about 20 years old, exposed himself to a group of three young girls in the underpass in Ecton Brook Road at about 4.30pm on Sunday, December 28.
After detailed investigations into the incident, officers have now released details of the man to the public in the hope that somebody will recognise him.
He was white, between 5ft 10in and 6ft and slim with short brown hair.
He was wearing a black hooded top and black trousers.
Although he ran towards the three girls, they managed to get away.
Witnesses, or anyone who knows anything about this incident, should call Northamptonshire Police on 101 or Crimestoppers on 0800 555111.