Police were looking for a man who was using binoculars to watch a woman who was walking her dog Friday morning at Stouffer Park in Ripon.
The incident occurred between 9:30 and 10:30 a.m. at the park, just east of North Manley Road.
The man was watching the woman before he approached and tried to start a conversation with her, according to Ripon police.
She notified a city park employee, who called police.
The man, who was described as white and in his 40s or 50s, left before officers arrived; he was driving an older model maroon Datsun pickup with a dog cage in the back, police said.
Investigators ask anyone with information about the man or his pickup to call the Ripon Police Department at 599-2102.