Man With Firearms Training Claimed He Fatally Shot His Wife By Accident While Cleaning Gun

The 911 call went out shortly after 9 a.m. on January 18, 2016 in Spokane, Washington. 

Dwayne Thurman, 44, claimed that he had accidentally shot his wife, Brenda, who was gasping for air. He didn’t wait for an ambulance. He and his daughter, Gabby, drove Brenda to the hospital.

She had a gunshot wound in the center of her chest, private investigator Ted Pulver told “Accident, Suicide or Murder,” airing Saturdays at 8/7c on Oxygen. Brenda, 43, was rushed into surgery, but she died from her injury. 

Detectives interviewed Gabby. She said she was upstairs sleeping and was awakened by a loud noise, followed by Dwayne yelling for her to come downstairs. Dwayne, a reserve deputy in a nearby county, told Gabby that he’d accidentally shot Brenda.

Because of his experience with firearms, she believed the shooting was intentional.

Detectives learned that Dwayne and Brenda met in the Army, where she was a military sniper. They’d been together for 18 years. 

After her years of service, she earned a master’s degree and became a counselor for the Veterans Administration. Dwayne also worked there, helping homeless vets get into housing.

Dwayne told investigators he had recently purchased the teal Glock 43 firearm that killed Brenda as a gift for her. They’d just taken it out to a shooting range for the first time and had firing issues. He said the gun was “stovepiping,” which occurs when a casing isn’t ejected after a gun is fired.

After going out for a pancake breakfast the next day, Dwayne started to clean the gun at the kitchen table, he claimed. Brenda, he told investigators, sat across from him and opened her laptop.

He started to dissemble the gun, and it went off. He was unsure if he pulled the trigger, claiming that there was no magazine in the pistol and that he believed it wasn’t loaded.

Law enforcement went to the Thurman house to investigate. They recovered the Glock, a single casing, and the laptop, which Dwayne had described. There were no signs indicating that a fight had occurred.

To determine if Dwayne was being truthful about the shooting and the stovepiping issue, detectives consulted a firearms expert. 

But right off the bat, the fact that Dwayne had military and law enforcement training with firearms, a red flag was immediately raised. A basic rule is to not point a gun at someone while cleaning it.

Investigators spoke with employees at the restaurant where the Thurmans dined. They reported no disputes were had and that the couple was “getting along famously,” said Jeff Humphrey, senior reporter, KXLY-TV Spokane.

At the shooting range, however, the rangemaster had not been notified that there had been any malfunction with Thurman’s gun. Detectives only had Dwayne’s word to go on that the gun had jammed.

During Brenda’s autopsy, the medical examiner removed a single bullet from her heart. The manner of death was ruled as accidental.

That ruling made the firearms inspection of the Thurman Glock 43 a lower priority, according to “Accident, Suicide or Murder.”

But as detectives worked the case, Gabby told them that Brenda suspected Dwayne of cheating on her. 

“He was in a marriage that wasn’t going the way he wanted it to go,” said John Love, deputy prosecutor, Spokane County, Washington. “That could have been a motive as to why he wanted her dead.”

When police confronted Dwayne with cheating allegations, he claimed that Brenda was having an affair with someone at the VA. He also said he was trying to salvage the marriage.

The case came to a standstill. But a week after Brenda was shot, Dr. John Marshall, chief of surgery at the VA Hospital, disappeared and was found dead. 

Dr. Suzan Marshall, his wife, reported him missing after he didn’t return from the YMCA. When she drove to the facility, her husband’s car was there, but he wasn’t. Security camera footage showed Marshall leaving the building in running clothes around 5:30 a.m.

A massive search on foot and by helicopter began at 11:30 a.m. 

“I was really just in this state of terror,” said Suzan.

The couple married during medical school and served as combat surgeons for the US Army. 

Dr. Marshall’s body was found a day later on a sandbar at the river very close to where police had set a command.

“It looked like he was sleeping on a sandbar,” said Pulver. “There was no blood. There wasn't a gunshot wound. There wasn’t any knife wound.”

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Detectives investigated the possibilities that Marshall had fallen or jumped off a nearby bridge or was murdered. 

But the medical examiner found no evidence of injuries related to a long fall, which made a suicide jump or push from the bridge unlikely. The examiner did uncover blunt force trauma to his chest.

The death was ultimately ruled an accidental drowning. 

 As a surgeon and medical expert, Suzan Marshall questioned that determination. She believed her husband was abducted and killed, she told producers. She hired Pulver to dig deeper. 

The deaths of two VA Administration employees within a week of each other raised the questions: Were the cases linked? Were Brenda and Marshall having an affair?

Although two may have run into each other on occasion, there was no indication they had any kind of unprofessional relationship, according to Pulver. That didn’t rule out the possibility that Dwayne may have suspected that, even if it wasn’t true, according to “Accident, Suicide or Murder.”

After a few months Marshall’s case was closed. Suzan reached out to Gabby and her brother Michael and offered them help. The siblings were frustrated that Dwayne benefited from their mother’s death benefits and that he was simply going on with his life.

In April 2017, Gabby and Michael filed a civil wrongful death suit against Dwayne, said Humphry. That put pressure on law enforcement to finally examine the gun that killed Brenda.

The firearms examiner determined that the pistol was not defective and that it was operating properly.

In June of 2017 Dwayne was charged with manslaughter. He pleaded not guilty, and his trial began in March 2018.

“We needed to show to the jury even Dwayne knew that he was not being as careful as he should have been with that gun,” said Love.

On May 3, 2018, Dwayne Thurman was found guilty of second-degree manslaughter. He was sentenced to five years in prison. 

Dwayne was not charged in the John Marshall case, which remains unsvolved. He was released from prison in September 2022.

To learn more about the case, watch “Accident, Suicide or Murder,” airing Saturdays at 8/7c on Oxygen.