Updated

Friendly fire apparently killed a New York state trooper in a gunfight that erupted as he searched a farmhouse for a suspect in the shooting of a colleague, officials said Friday.

Trooper David C. Brinkerhoff was fatally shot Wednesday as he and six other members of the force's elite mobile response team searched a Catskill-area house where the armed suspect had holed up.

The 29-year-old and another trooper were shot by the suspect, Travis Trim, as the two entered the upstairs bedroom where the man had two guns, but it is one of the about 70 police rounds fired that officials believe killed Brinkerhoff.

"The fatal wound was made by a .223 (caliber) tactical round that was believed to have been fired by an MRT member," said acting State Police Superintendent Preston Felton.

Felton said Friday an autopsy showed that Trim, 23, also was killed by troopers, shot once in the head and twice in the chest. "It's our belief he was killed almost instantaneously," he said.

The Margaretville farmhouse was destroyed hours later in a fire that erupted as troopers, unaware that Trim was dead, closed in on the suspect. His badly burned body, holding a rifle, was found inside later.

Felton said Friday that a police tear gas round that landed on a bedspread appears to have started the fire.

The seven troopers were wearing body armor and carrying assault rifles as they entered the farmhouse, a vacant seasonal residence where Trim had tripped an alarm that morning, police said. The house was several hundred yards from where Trim had abandoned a stolen minivan the afternoon before.

Trim, hiding in an upstairs bedroom, shot Brinkerhoff in the chest with a small-caliber handgun and Trooper Richard Mattson in the arm with a .30-30 rifle as they closed in, Felton said. Four troopers also fired, Felton said, without elaborating on whether Brinkerhoff and Mattson were among them.

The bullet from Trim's handgun hit Brinkerhoff's body armor, possibly knocking him down to one knee. Brinkerhoff, who was wearing a Kevlar helmet, was then shot in the back of the head with a bullet that may have been a ricochet, Felton said.

"In a firefight such as this, and our members are highly trained, what it appears happened here is that Trooper Brinkerhoff was struck in the chest and was knocked back," Felton said. "Other members came to his aid and started to return fire at the shooter. At some point Trooper Brinkerhoff ended up getting hit by a round.

"Common? No," Felton said. "This was a very volatile situation."

The troopers grabbed their wounded colleagues and backed out. The house was surrounded most of Wednesday while police sent in a robot to probe.

Mattson remained in serious condition Friday at Albany Medical Center Hospital.

The new details about the deadly encounter were based on "an autopsy and preliminary forensic review," Felton said, adding that the full analysis of the information is not yet complete.

Trim had been on the run since Tuesday, when he shot a trooper after he was stopped driving the stolen minivan. That trooper's body armor prevented him from being seriously hurt, police said.

Trim's grandmother said the results of the preliminary investigation change little about her shock at her grandson's actions.

"It would make me feel a lot better but I'm still disgusted that he would be shooting at troopers," said Ruth Trim, 76, of Dickinson Center, N.Y. "We need our troopers. It's an awful world out there."

Trim had been on probation for a driving while intoxicated conviction. A warrant was issued for his arrest in December after he stopped seeing his probation officer and was charged with marijuana possession and buying beer for underage people.

However, the director of St. Lawrence County's probation department and local police told the Ogdensburg Journal that they never received the warrant, issued out of Canton Village Court.

Brinkerhoff is the third trooper to be shot and killed in the line of duty since March 2006 -- a tragic stretch of time for the state police in which two other on-duty troopers died in vehicle accidents and another was killed while on foot patrol in Iraq.