A smirking flasher is on the loose in Chesterfield.
Police said a 14-year-old girl and her friend were walking near to the entrance of Holmebrook Valley Park when they saw a man.
The man walked past the girls and exposed himself to them.
He ran into the park, turned around and smirked at the girls before walking into the woods, police said.
The man was described as white, around 60-years-old, more than 6ft tall, of a skinny build.
He had short grey hair and stubble on his face and was wearing short, high-waisted green shorts, a white T-shirt, white sports socks, white trainers and a black watch.
Witnesses or anyone with information to the indecent exposure – which happened between 3pm and 3.50pm on Thursday, November 12 – should call PC Cheryl Slater on 101, quoting crime reference number 49915/15, or Crimestoppers on 0800 555 111.