Conflicting testimony of expert witnesses can sink an insanity defense

They can enlighten or paralyze a jury. And though they often conflict wildly, the opinions of expert psychologists and psychiatrists can determine the outcome of a murder case with an insanity defense.

In the Naveed Haq case, which ended in a mistrial Wednesday, it seems jurors became hopelessly mired in a bog of conflicting diagnoses and medical opinions that bubbled up from a handful of expert witnesses during six weeks of testimony.

Conflicting expert testimony is one of the major challenges of a successful insanity defense, said Jim Hardisty, professor of law at the University of Washington.

Insanity defenses are rare. One of the reasons is that in Washington, the burden of proof is on the defense. Jurors often find it difficult to decide a defendant was insane when much of the evidence presented by both sides conflicts so strongly, Hardisty said.

"You're dealing often with mushy language, experts on both sides. If the jury isn't sure, the burden is on the defense: The defense has to persuade the jury that, more likely than not, the insanity defense is met. If jurors are 50/50, they have to decide for the prosecution."

In the Haq trial, doctors testifying for both sides clashed on many fronts and provided a range of differing opinions, from Haq's diagnosis — bipolar vs. schizoaffective disorder — to his mental state before and during the shootings — depressed but aware vs. manic and insane.

The witnesses even interpreted the observations of Haq's family members differently, and gave disparate weight to Haq's story of hearing voices before and during the shooting, propelling him forward.

How a case is prepared

Attorneys understand that going into a case such as Haq's, one with an insanity defense, their challenge will be to present at trial more believable experts than the other side does.

Even before a trial, as soon as defense attorneys indicate they want to pursue a not-guilty-by-reason-of-insanity defense in a criminal case, an evaluation process clicks into gear, said Ian Goodhew, deputy chief of staff for the King County Prosecuting Attorney's Office. Defense attorneys will hire their own psychologists or psychiatrists who evaluate the defendant and prepare medical findings.

The state then retains its own experts — often from Western State Hospital — who conduct their own assessment.

If the prosecution experts dispute the findings of the defense experts, the state will pursue the case to trial, Goodhew said.

If the state experts agree with the defense experts' medical diagnosis, "that's the situation where we agree to a not-guilty-by-reason-of-insanity plea," Goodhew said. Attorneys on both sides will then usually fashion an agreement — later approved by a judge — for a defendant's indefinite commitment to a mental hospital.

Some previous cases

Since the late 1990s, there have been a handful of insanity-defense cases in King County murders.

Sometimes, the state fights the insanity defense, such as in the case against Ronald Matthews, found guilty by a jury of aggravated first-degree murder in the 2002 shooting death of King County sheriff's Deputy Richard Herzog.

The state agreed with doctors that Matthews was psychotic when he grabbed Herzog's gun on a Newcastle street on June 22, 2002, and shot the deputy four times. But they pursued the case to trial, arguing that Matthews was only in that state because he had smoked crack hours before. He was convicted and sentenced to life in prison.

But in most successful insanity defenses, a judge renders the verdict after the state opts not to pursue a trial. Recent high-profile cases include:

• Joshua Hoge, a Kent man who killed his mother and half-brother in June 1999.

• Dan Van Ho, who stabbed retired Seattle firefighter Stanley Stevenson to death after Stevenson left a Mariners game in August 1997.

• Marc Gerson, a Redmond man who set fire to his parents' house in January 1999, killing his sister and nephew.

• Thomas Gergen of Shoreline, who had been charged with the January 2003 murder of his pregnant wife.

• Samson Berhe, found not guilty last month of murdering Newport High School tennis coach Mike Robb in June 2005.

Such an acquittal means prosecutors cannot refile charges against the person even if he or she is one day released from Western State Hospital.

How long is enough?

And it's not a guarantee that a patient sent to Western after being acquitted of murder will remain there forever. Washington law allows for the civil commitment of an acquitted person in a mental hospital as long as that person is thought to be a danger to society, for a minimum of three years and up to the maximum possible sentence for any applicable criminal charges. But after an acquittal, "there's no longer any criminal jurisdiction over the person, and that's sometimes our concern," said Goodhew. "We still want to make sure that this person, regardless of their medical diagnosis, is not a harm to anyone."

That was the case with Gergen, who in 2004 was found by a judge to be not guilty by reason of insanity of killing his pregnant wife, Kari Osterhaug, and was civilly committed for an indefinite period of treatment.

Osterhaug's family said they were led to believe that the commitment would last a very long time.

But in March, Gergen's doctors at Western State Hospital petitioned for his release, saying Gergen — who had been diagnosed with schizoaffective disorder — had made remarkable improvement.

Prosecutors fought the petition, and Judge Michael Hayden denied release, saying he was not convinced the public would be safe if Gergen were released.

"Yes, [Gergen] did not know right from wrong at the time of the homicide. But is five years enough? Is 10 years enough?" Goodhew said. "From our perspective, when you talk about a homicide, you think of a 20- or a 25-year sentence."

Natalie Singer: 206-464-2704 or nsinger@seattletimes.com

Seattle Times news researchers Miyoko Wolf, David Turim, Gene Balk and Justin Mayo contributed to this report.