Gentle giant sucker-punched into a fight or angry brute bent on violence?

Those were the dueling portraits of Thomas Junta, the hockey dad accused of beating another father to death over a scrimmage, presented Thursday in opening statements of his manslaughter trial in Cambridge, Mass.

Junta, a 44-year-old truck driver, faces 20 years in prison if convicted of the death of Michael Costin. Costin, 40, was informally refereeing boys, including his three sons and Junta's son, at a July 5, 2000, pick-up hockey game. Junta objected to rough play on the ice and after the game got into two separate scuffles with Costin, who had dismissed his concerns with the words, "That's hockey."

During the second scuffle, Junta sat atop Costin, whom he outweighed by 100 pounds, and punched him multiple times, knocking him unconscious. Costin later died from his injuries.

Prosecutor Sheila Calkins told jurors she planned to call many eyewitnesses, including Costin's sons and rink staff, who would describe the fatal fight. A rink manager ordered Junta out of the arena after the first fight, the prosecutor said, but a few minutes later he came back in, pushing past the assistant manager who told him to leave.

Calkins

"She'll tell you that he didn't even appear to see her and he pushed her out of the way," said Calkins, who added that the shove left the assistant manager with a serious bruise.

"The defendant repeatedly punched Michael Costin in the head area and then intentionally took his head and hit it into the floor of the arena," said Calkins. The prosecutor said medical experts will testify that the assault ruptured an artery near Costin's spinal cord, causing his death.

But in a long, detailed opening that stood in contrast to the prosecution's brevity and broad strokes, defense lawyer Thomas Orlandi said the victim instigated the fatal fight. He told jurors that Costin ambushed Junta — whom he described as the hard-working head of a "hockey family" — with a sucker punch as he reentered the arena to escort his son to safety.

Junta

As soon as he opened the door, "the punch is flying toward his face," said Orlandi. Junta was terrified Costin was "a karate or a nut," the lawyer said, and when Costin continued to attack him, Junta protected himself.

"Three punches — one, two, three. It's over. Mr. Costin goes into a defensive pose and when he does, Mr. Junta stops," said Orlandi.

In an apparent attempt to brunt the prosecution's strongest piece of evidence, the defense lawyer repeatedly addressed the dramatic size difference between the 160-pound victim and the 275-pound defendant. He mentioned Costin's weight several times as he described the man's alleged violent behavior — punching Junta during the first fracas, snatching the chain from his neck, ripping Junta's shirt and kicking him in the shins with his skate blades.

Before openings, the jury of 10 women and four men toured the Burbank Ice Arena, site of the killing. They will begin hearing from witnesses Friday morning.

The trial is being broadcast live by Court TV.