Napa County prosecutors have decided that no one will be charged with the June 2007 shooting death of Coombsville resident Stephan Williams, 64.

In an e-mail released Thursday, Napa County District Attorney Gary Lieberstein called Williams’ death an accident.

After the June 18 incident, Timothy Martin, 37, who was Williams’ former stepson and shared a Fourth Avenue home with him, was booked into county jail for murder. He was never charged and was released June 20, with prosecutors saying there was insufficient evidence against him. The case was sent back to the Napa County Sheriff’s Department for further investigation.

The sheriff’s department wrapped up its probe in December and forwarded its findings to Lieberstein. On Thursday Lieberstein wrote “there is insufficient evidence to conclude that Mr. Martin’s actions on the evening of this tragic accident, which ultimately caused the death of his father, were the result of any criminal violation. Therefore, criminal charges will not be filed against Mr. Martin and our office considers this case closed.”

In the e-mail, Lieberstein said the sheriff’s investigation was extensive and thorough, and that his office closely considered the facts “and the law regarding involuntary manslaughter, which includes gross criminal negligence.”

Timothy Martin’s twin brother, Matt Martin, declined to comment Thursday.

Uncooperative witness

The night of the shooting, sheriff’s deputies found Williams’ body in the backyard of his home at 1185 Fourth Ave. He had been killed by a gunshot wound to his head.

Timothy Martin was arrested later that night. Deputies also retrieved a .20-gauge shotgun in the backyard believed to have been used to fire the fatal shot.

Lt. Jean Donaldson, who heads the investigation unit of the sheriff’s department, said an altercation involving others occurred at the home that night. Garth Schooler had come to the house looking for his wife, who was staying with Williams and Martin.

Schooler, Martin and Williams were on the back porch. Martin ordered Schooler to leave the property, Donaldson said.

Then, Donaldson said, Martin “armed himself with the .20-gauge shotgun. The gun went off accidentally, striking Mr. Williams.”

The obituary submitted to the Register in June by Williams’ family said he had “passed away after an accidental shooting while protecting a woman.”

Donaldson said the case was difficult because one of the witnesses was “not very cooperative and didn’t want to talk to us. It made the investigation drag on.”

Martin is Williams’ ex-stepson. His mother and Williams were divorced, but Martin, his brother and sister remained close to Williams.

Martin lived with Williams, and his brother lived at the Fourth Avenue home off and on.

Williams was an industrial engineer who had worked for the state and private companies, and was a collector of Studebakers, Packards and antique Fords.