Several prescription drugs in Judy Hebert's blood system together created a clinical phenomenon that can be quite serious and is known as "serotonin syndrome," a medical expert said Tuesday.
When the 58-year-old Pasco woman died from a gunshot wound in 2011, tests showed she had anti-depressants, chronic-pain relievers, sleeping aids, cannabis and alcohol in her body.
Some medications, particularly the Valium, were at levels considered quite high for therapeutic levels, Dr. Robert M. Julien told jurors in the murder trial of Tashia Stuart. He added that he normally would see some of those levels in a person tested after bedtime, not in the middle of the afternoon.
The combination can be fatal, Julien said, though he acknowledged that in this case there were other reasons for Hebert's death.
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Julien was called out of order as a defense witness because of his limited availability.
Stuart's lawyers had scheduled Julien because they anticipated putting on their case this week. However, prosecutors still are presenting evidence and don't expect to wrap up until Friday.
Stuart, 40, is accused of trying to kill her mother by dropping a heavy bin of books on the older woman's head, then fatally shooting her two weeks later.
The trial started May 28 in Franklin County Superior Court.
Julien was on the stand Tuesday for almost 30 minutes. He is a retired anesthesiologist who in 1975 wrote the first textbook on psychopharmacology, which looks at how drugs affect a person's brain and their behavior.
The Lake Oswego, Ore., doctor said he was asked by attorneys Bob Thompson and Peter Connick to interpret the significance of Hebert's toxicology results.
Stuart claims her mother tried to attack her with a hatchet March 3, 2011, so she fired the gun in self-defense. She has denied being in the Salmon Drive home's garage on Feb. 20, 2011, when Hebert was injured by the falling bin.
Thompson told jurors in his opening statement that Hebert -- who was on drugs for pre-existing medical conditions, in addition to the new head and neck injury -- overmedicated herself which led to irrational behavior.
Hebert's blood-alcohol level when she died was 0.09 percent, just above the legal limit to drive in Washington.
Julien testified that she had "just a touch" of cannabis in her blood. He couldn't say if it was from smoking pot recently or perhaps days before, and didn't know if she had a medical marijuana card.
As for Hebert's high levels of prescription drugs, Julien said he did not know if it was from her taking extra amounts of drugs or because she had Valium in her system which could raise the other levels.
But together the drugs can increase the serotonin in a person's brain and lead to behaviors resembling someone on LSD, he said.
Symptoms of serotonin syndrome include agitation, increased blood pressure, hallucinations, disorientation, confusion, restlessness, fevers and chills, and ultimately a breakdown in proteins and kidney failure.
Prosecutor Shawn Sant questioned if there's a test to see if a person has been experiencing serotonin syndrome.
Julien said the blood tests to see what drugs are present and at what levels must be correlated with a person's behavior.
In this case, since he wasn't in the home more than two years ago to see Hebert and couldn't interview her, they would have to depend on others about Hebert's behavior to see if it was consistent with the symptoms. But Julien said he only was asked to interpret the meaning of lab results and would have to leave the rest with the court.
"Isn't that an important part to see if someone is going through serotonin syndrome?" Sant asked.
Julien agreed that interviews with people who had regular contact would be a part of the diagnosis to see if they observed any symptoms in Hebert.
He clarified for Connick that things like confusion, paranoia and depression are easily visible and, though a layman not familiar with the syndrome might not pick up on the symptoms, a physician hopefully would see something was wrong.
Dr. Daniel Selove, a forensic pathologist from Everett who performed the autopsy, said Hebert's cause of death was the gunshot wound to the chest, not the drug levels in her system.
Selove added that the bullet went through Hebert's left thumb before entering her upper chest, passing through a lung, severing an artery and eventually hitting the spine. At that point, she would have lost control of her lower body and crumpled to the floor in the direction she was moving, he testified.
Selove said he doesn't believe the indentation in Hebert's skull directly below a "chop wound" could have killed her. It is believed that wound was caused by a hatchet that was found at the scene, along with a .357 revolver.
The jury Tuesday also heard more testimony from forensic scientist Mitch Nessan, along with Pasco police Detective Justin Greenhalgh and Sgt. Jeff Harpster.
The attorneys need to address a couple evidence issues with Judge Cameron Mitchell before testimony starts today, so jurors will return to the Franklin County Courthouse at 10 a.m.
-- Kristin M. Kraemer: 582-1531; email@example.com; Twitter: @KristinMKraemer