A 38-year-old Forestville man with a bizarre criminal history is suspected of shooting his brother to death with a rifle in the home where they both lived with their mother.

Shaun Michael Gallon was jailed Friday night on suspicion of fatally shooting his younger brother, Shamus Gallon, 36, a Sonoma County Sheriff’s official said.

He was apprehended shortly after the shooting was reported, about 7:30 p.m., at a gas station on the outskirts of Guerneville. He was booked on suspicion of murder and held without bail at the Sonoma County Jail, Sgt. Spencer Crum said.

Gallon, who served prison time for shooting a handmade arrow through a car roof at two men in 2009, was also held on suspicion of being a felon in possession of a firearm and possession of an assault weapon, according to jail records.

Crum said the motive for the shooting remains unclear.

“There doesn’t appear to be an altercation of any significance that led to the shooting,” he said in a statement.

Gallon was arrested after questioning by detectives who worked all night on the case.

Deputies were summoned around 7:15 p.m. to the multi-level home in the 9800 block of River Road by the men’s mother, whose name was withheld by the sheriff’s department.

She said her son Shaun Gallon had just left home with a rifle and also said her younger son Shamus was shot with a rifle, Crum said.

When deputies arrived, emergency responders were performing CPR on the younger brother. Resuscitation efforts were unsuccessful and he died at the scene, according to the sheriff’s department.

Gallon’s mother provided deputies with a description of the white Ford Windstar minivan that Shaun Gallon was driving.

Deputies spotted it going westbound on River Road near Korbel Champagne Cellars, and as one of the deputies braked hard to make a U-turn to follow it, a second deputy in line failed to slow and collided with the first deputy’s vehicle, according to Crum. There were no injuries but both patrol cars were inoperable.

A third deputy in the area was able to locate the suspect’s vehicle at the MD Gas and Food station in Guerneville.

Gallon was taken into custody without incident, according to the sheriff’s department.

The rifle believed to be used in the shooting was found in the van, Crum said. He declined to identify the type of rifle. He said there were no other suspects in the shooting.

Gallon was convicted in 2009 of shooting a handmade arrow through the roof of a car parked in front of his Guerneville apartment, striking one of two men sitting inside.

He was sentenced in early 2010 to three years in prison for the incident that triggered a two-day SWAT action that shut down part of Guerneville while deputies surrounded an apartment, believing he was still inside.

Gallon turned himself in to authorities five weeks later and was charged with assault with a deadly weapon.

The victim, James McNeil of Monte Rio, was not seriously injured.

You can reach Staff Writer Clark Mason at 521-5214 or clark.mason@pressdemocrat.com. Guy Kovner can be reached at 707-521-5457 or guy.kovner@pressdemocrat.com. On Twitter @guykovner.