A police officer testified Friday in the manslaughter trial of a man accused of fatally beating another hockey father that he saw the victim lying motionless and surrounded by children when he arrived at a suburban community ice rink after a fight between the two men.

Reading Police Sgt. James Cormier was the first witness to take the stand in the trial of Thomas Junta, 42, who is accused of beating Michael Costin, 40, to death after their sons' youth hockey practice in July 2000.

Costin died the day after an argument over rough play at the Burbank Ice Arena in Reading, a suburb 15 miles north of Boston.

Cormier said he found Costin lying motionless, attended by another adult, with his eyes open and staring straight ahead. He said Costin was "surrounded by a lot of children" ranging in age from seven to 15.

"It was pretty traumatic," Cormier said.

He asked an attendant to move the children away from the scene, then knelt down to try to revive Costin – without success.

Several young players saw the fatal beating. Eleven children, ages 11 to 15, who were at the rink that day are included on the prosecutor's list of potential witnesses, including sons of both men.

Cormier was the first officer on the scene. He said he found Junta with his shirt ripped and a scratch on his face.

Cormier said he asked Junta if he was a participant in the fight and Junta nodded or said yes. He then asked Junta where the other man was.

"His response to me was that he was inside laying down," Courmier said.

Both sides in the case agree that Junta argued with Costin, then left the rink with his son, returned, and a second altercation broke out. But attorneys for the two sides described very different scenarios of what happened next.

Junta's attorney told the jury in opening arguments Thursday that Junta was defending himself from a "sucker punch" thrown by the victim, while prosecutors said Junta pounded Costin's head on the floor until he lost consciousness.

Prosecutors described Junta, a 6-foot-1 truck driver, as the aggressor, whose size overpowered the smaller Costin, who was 125 pounds lighter than Junta. The defense says otherwise.

Under questioning from Junta's attorney on Friday, Thomas Orlandi Jr., Cormier said Junta was polite and cooperative when he reached the scene of the fight.

Throughout the proceedings Junta looked somber, staring down and often putting his hand to his brow.