Oregon Public Broadcasting

A Clackamas County man accused of killing his stepson last summer, has won a partial victory in his appeal to the Oregon Supreme Court. Kristian Foden-Vencil reports.

Steven Petersen is claiming that he suffered from diminished mental capacity on the night he's accused of murdering Michael Chapman.

Clackamas County Court ordered Petersen undergo a psychiatric exam -- to determine his mental state.

It also required that he answer all questions concerning his thoughts and acts quote: "at or immediately near the time" of the killing. 

Petersen's lawyer appealed, saying that would violate his client's right against self-incrimination. Lawyers for the state say Petersen waived that right when he testified to his own mental health expert.

The Clackamas County judge found that if Petersen didn't submit to an interview with a state expert, then he couldn't make his mental state an issue at trial.

His attorney appealed to the Oregon Supreme Court.

That panel has now told the lower court that Petersen's mental state is an issue. But it also said Peterson couldn't stop a state mental health expert from asking him questions -- he just doesn't have to answer them.