BOSTON—A Massachusetts man convicted of beating another father to death at their sons' hockey practice asked a federal appeals court Tuesday to overturn his conviction, arguing that prosecutors withheld evidence that could have weakened the testimony of a key witness.
Thomas Junta, of Reading, is serving a 6- to 10-year sentence for involuntary manslaughter in the death of Michael Costin in July 2000. The case drew widespread attention to the problem of parental violence at youth sporting events.
Junta testified that he confronted Costin after his son was elbowed in the face during a practice Costin was supervising.
Prosecutors said that Junta, a 6-foot-1, 270-pound truck driver, overpowered the 160-pound Costin and pounded his head on the floor until he lost consciousness. Costin was declared dead the day after the fight.
In arguments Tuesday before a three-judge panel of the 1st U.S. Circuit Court of Appeals, Junta's lawyer, Chauncey Wood, said prosecutors withheld evidence that could have been used to challenge the testimony of a medical examiner who said Costin's death was caused by "substantial force."
Wood said that prosecutors failed to disclose details of what medical examiner Stanton Kessler said about Costin's injuries during a professional conference about a year before Junta's trial. Wood said Kessler implied during the conference that Costin had suffered "only minor blows to the head."
In order to convict Junta of involuntary manslaughter, the jury had to find that he knew or should have known that the beating he was giving Costin could endanger his life.
"It all comes down to the degree of force used in the punching," Wood said.
But Assistant Attorney General James Arguin said there were no inconsistencies in the medical examiner's testimony. He said Kessler testified during Junta's trial that there were 15 areas of trauma to Costin's body and that there was no doubt that the injuries were caused by "substantial force."
Junta testified that he acted in self-defense. He said he fought back after Costin threw a "sucker punch" at him, jumped on him and continued to hit and kick him after the two men fell to the floor.
Two witnesses said Junta struck Costin repeatedly in the head while pinning him to the thinly matted floor of the ice arena.
The court did not indicate when it would rule.
Junta's argument has previously been rejected by the state Appeals Court and U.S. District Court Judge William Young.