Outrage over psychotic killer Phillip Paul’s three-day getaway last month is rare political currency. Expect state lawmakers to find a way to spend it.

They could do worse than state Sen. Mike Carrell’s proposal to give judges and juries more options when deliberating the guilt of mentally ill defendants. The Lakewood Republican first floated the bill last session, before Paul walked away from an Eastern State Hospital group outing to the Spokane County fair.

Now he’s finding new support. Gov. Chris Gregoire and the secretary of the state Department of Social and Health Services both mentioned creating a new criminal verdict for the mentally ill in the days after Paul escaped. Rep. Chris Hurst, an Enumclaw Democrat who chairs the House Public Safety Committee, has also thrown his support behind the idea.

State lawmakers seem destined for a debate over an alternative to “not guilty by reason of insanity” and the good old “guilty” verdict.

Fourteen states allow for an intermediate finding of “guilty but mentally ill.” It’s intended to be used in cases in which the defendant’s mental illness may have affected his judgment or conduct, but not to the extent that he was completely unable to distinguish right from wrong.

People convicted as guilty but mentally ill go first to state psychiatric wards for treatment. If their illness improves before their criminal sentence is up, they serve the remainder of their time in prison.

Legislators should look before leaping on this bandwagon. Current law hasn’t prevented juries from convicting plenty of mentally ill criminals. State corrections officials estimate that about 20 percent – or 3,600 – of the state’s 18,000 prisoners are mentally ill.

By contrast, fewer than 100 patients committed to state mental hospitals are there because they were found not guilty by reason of insanity. In general, the insanity defense is successful in less than half of 1 percent of felony cases.

If, after a hard look, lawmakers decide a third option is really needed, they should craft it carefully. Guilty but mentally ill is only as good as lawmakers define it and as judges explain it.

Many mental health experts are concerned that jurors with no legal or psychiatric training are forced to judge degrees of mental illness and to guess at the meanings of legal terms like “substantial capacity.” Those experts also worry that the guilty but mentally ill verdict becomes a shortcut for juries that don’t want to wrestle with the difficult issues raised by an insanity defense.

That effect becomes especially worrisome in those states that don’t make serious mental illness a mitigating factor at sentencing. Juries are led to believe they are delivering a less-than-guilty verdict that in fact has the same force as a straight guilty plea when it matters most.

A mitigated conviction should come with a mitigated sentence. Those who remain violent for psychiatric reasons could still be committed involuntarily, as they are now.

Whatever the Legislature does, it should beware trying to criminalize mental illness. Doctors who examined Phillip Paul after he strangled an elderly neighbor described a man overcome by paranoid schizophrenia. To them, he seemed to be in the grip of the voices he heard in his head and truly believed he was killing a witch, not a person.

Some cases will continue to merit the insanity defense. In those instances, the public depends on rigorous psychiatric monitoring and use of existing civil commitment laws to ensure that the violent psychotics aren’t given a chance to harm themselves or others.