Police investigating a series of reported sexual assaults in Watford have released CCTV of a man wearing distinctive Simpsons cartoon slippers.
Officers said an offender has been approaching women and grabbing their buttocks, and is believed to have assaulted six women since June.
Dectectives said the incidents have occurred around the Vicarage Road, Wiggenhall Road and Exchange Road areas of Watford.
Police working as part of Operation Cortes have increased patrols around the town while they try to trace the predator.
Detective Sergeant Matthew Waylett, from the Watford Local Crime Unit, said: "We believe these incidents are linked due to the description of the offender, the nature of the incidents and the locations they have taken place.
"I can reassure residents that I have a team of detectives working hard to identify, trace and arrest the man responsible. We have also increased police patrols in the area to protect the public and to reduce the potential of further similar incidents."
Officers have released an image of a man they wish to speak to in connection with the investigation.
Sergeant Waylett added: "The man pictured may have vital information about what happened and I would urge the public to contact us if they can identify him. He is wearing a distinctive pair of Simpsons cartoon slippers.
"I would also like to speak to anyone who believes they may have witnessed these incidents or has been approached by a man in the area in similar circumstances to contact us.
"Whilst our investigations take place I would urge women and girls in the area to take note of some safety advice, including remaining alert when walking alone, being aware of your surroundings and sticking to busy, well lit areas."
Anyone with information is asked to contact the local crime unit at Watford Police Station via the Herts Police non-emergency number 101, quoting Operation Cortes.
Alternatively call Crimestoppers anonymously on 0800 555 111.