A 12-year-old hockey player whose father is accused of beating another hockey dad to death testified Tuesday that he saw his father flip the man off his back and then, kneeling above him, punch him three times.

Thomas Junta, 44, is accused of pummeling Michael Costin to death after an argument over rough play at their sons' hockey practice on July 5, 2000. Costin, 40, never regained consciousness and was pronounced dead the next day.

Quinlan Junta testified that he ran to the rink lobby and saw his father and Costin fighting.

"I saw my dad, and then I saw Mr. Costin on his back," Quinlan said. "I saw him flip (Costin) over his shoulders. He went on the floor.

"I just like stood there," Quinlan said. "My dad hit him three quick times, really quick."

On cross-examination, prosecutor Sheila Calkins asked Quinlan: "You yelled out to your dad, 'Stop,' didn't you?"

He answered simply, "Yes."

The prosecution rested its case at midday Tuesday after emotional testimony from a woman who witnessed the fight.

Virginia Brings, whose grandchildren were at the skating rink, testified Tuesday that she screamed "Stop, please stop!" as Junta continued to pound Costin into unconsciousness.

"I remember yelling to Mr. Junta, 'He's not responding, he's not responding. Don't hit him any more,"' she testified.

Junta claims he hit Costin in self-defense. But prosecutors say Junta, a 270-pound truck driver, used his size to overpower the 160-pound Costin, then pounded his head on the floor until he lost consciousness.

During cross-examination, defense attorney Thomas Orlandi Jr. questioned whether Brings was certain of the number of punches Junta threw, given that she was so upset.

"It's something that I'll never forget. He went on and on," she said without hesitation." I remember thinking at the time: he's either going to kill this man or he's going to have brain damage."

Earlier Tuesday, a college hockey player who helped pull Junta off Costin testified that Costin threw the first punch, and that Junta appeared to stop hitting him when Costin made a defensive move.

Ryan Carr, 21, said Costin put up his hand after Junta landed about three punches to Costin's head.

Orlandi asked Carr if Junta then instantaneously stopped hitting Costin.

"He appeared to stop, yes," Carr said.

His jaw trembling, Junta bit his lower lip and wiped his eyes with a tissue when Carr described how Junta left the rink and sat outside, waiting for police.

He fidgeted but maintained his composure as his son testified for about an hour. The judge adjourned court for the day after Quinlan's testimony.

The sixth-grader described the rough play that provoked the first argument between his father and Costin.

Quinlan said the opponents — older players — started hitting him and his friends when they started to outscore them. He said he saw his father tell Costin, who was supervising the practice, to control the children.

"He said, 'Hockey's about hitting,"' Quinlan testified. "My dad said, 'That's (expletive). It's about having fun."'

Quinlan said he was elbowed in the face by an opponent as he left the ice, and that further infuriated his father. He said Junta and Costin argued again in the doorway of the locker room.

"He was kicking at my dad and trying to get at his neck. ... He like pulled off his chain," Quinlan said.

Junta left the rink after that first fight. He returned minutes later and the men had a second, more violent fight. Witnesses have differed on what happened in the second fight.

Brings' testimony appeared to bolster that of rink employee Nancy Blanchard, who on Monday described being shoved aside by Junta as he re-entered the arena and set upon Costin.

Blanchard said she saw Junta hit Costin at least six or seven times.

"(Junta) put his left knee on Mr. Costin's left shoulder," Blanchard said, choking up as she spoke. "He had (Costin's) head in his left hand. He was punching Mr. Costin's head and neck repeatedly."

"I think I remember screaming, 'You're going to kill him,"' she said.