A worker at the Sonoma Developmental Center for mentally disabled adults was in custody Tuesday on suspicion of exposing himself to a female patient, Sonoma County sheriff's officials said.

Rue LeRoy Denoncourt, 53, of Sonoma is accused of leading a 39-year-old woman into a bathroom and exposing himself to her, said Sgt. Cecile Focha with the sheriff's sexual assault unit.

The woman has the capacity of a 4-year-old child, Focha said.

Another employee witnessed the lewd act and alerted staff at the Arnold Drive campus in Eldridge, Focha said. They called the sheriff's Sonoma Valley substation at 7:25 p.m. Friday.

Denoncourt was arrested late Friday and remained at the Sonoma County Jail in lieu of $75,000 on suspicion of committing a lewd and lascivious act by a caretaker upon a dependent adult, endangering the health of a dependent adult.

Denoncourt has worked as a psychiatric technician for 27 years at the center, Focha said.

A judge issued an emergency protective order prohibiting Denoncourt from contacting the patient.

He is scheduled to be arraigned at Wednesday.