Portland Police Officer Chad Wilcott has resigned after an investigation into allegations that he made inappropriate sexual comments to one woman and sexually assaulted another.

A criminal inquiry by the Multnomah County District Attorney's Office concluded there wasn't enough evidence to convict Wilcott, a seven-year veteran. But an internal DA's office memo also says Wilcott will be resigning as a result of the police investigation.

"The resignation is appropriate given the misconduct alleged and the apparent breaches of propriety in his police conduct,'' Deputy DA Pat Callahan wrote. Wilcott's attorney did not return WW's telephone messages, and Wilcott has an unlisted number.

The investigation began after March 2, when Wilcott arrested Barbara Biando's ex-boyfriend following a dispute at her North Portland home. She told police the officer demanded that she lift her shirt and "show me your tits," which she said she did.

Callahan wrote there wasn't enough evidence to support Biando's claims, and that some charges of harassment or coercion wouldn't stick. He also cited Biando's drug use in the decision not to prosecute.

Wilcott also faced investigation for a March 17 incident where a woman, Melinda Purtty, accused him of sexually abusing her in his patrol car. Wilcott was placed on administrative leave. Again no charges, due to a lack of physical evidence and Purtty's alleged alcohol consumption and prior criminal conviction.

Wilcott resigned April 22. Police will not release investigation reports until an internal inquiry ends.

North Precinct Cmdr. Cliff Madison wrote Wilcott's colleagues promising a thorough investigation and encouraging support for Wilcott "during this very demanding professional and personal time."