The man who beat another father to death after arguing at their sons' hockey practice goes on trial for manslaughter Wednesday — and their boys are expected to testify about the deadly fight.

Thomas Junta is charged in the July 5, 2000, killing of Michael Costin at the Burbank Ice Arena in Reading. Junta, who claims Costin was the aggressor in the fight, will testify in his own defense, according to his lawyer, John O'Connor.

Costin, 40, was supervising a hockey practice of boys about 10 years old that included his three sons and Junta's son.

Junta, 42, was watching from the stands. Prosecutors say Junta became enraged when he saw body-checking in what was supposed to be a non-contact scrimmage. The two men argued on the ice, then brawled in a hallway.

Junta left, but returned a few minutes later, and a second fight broke out. Prosecutors allege that Junta — in front of several children — pinned Costin down and banged his head against the floor until he lost consciousness. Costin died two days later.

The death drew national attention amid a growing number of cases involving parental violence at youth sporting events.

Junta plans to argue that he was acting in self-defense, his lawyer says.

The defense had wanted to introduce Costin's psychological history, including records that showed he was taking antidepressants. But Middlesex Superior Court Judge Charles Grabau rejected that request, and the state's Supreme Judicial Court agreed the jury should not be allowed to hear about Costin's psychological records.

Grabau also prohibited Junta's attorneys from introducing evidence about prescription drugs found in Costin's pockets and other medications that were prescribed for him.

Prosecutors are expected to call attention to Junta's size: 6-1 and about 275 pounds, compared to Costin, who was 6 feet and weighed 150 pounds. They also said at least one son from each side will testify.

Violence among parents and coaches has worsened over the last decade, according to the National Alliance For Youth Sports, a nonprofit organization in West Palm Beach, Fla.

"You have to have the maturity to deal with the emotions of having your child involved in sports, but unfortunately we have some parents on the sidelines screaming and yelling," said Fred Engh, the group's president. "If you don't have the maturity, then you shouldn't be allowed to participate."