Published: Apr 09, 2010 8:32 PM EDT

WOBURN, Mass.  - Figure skater Nancy Kerrigan's brother pleaded not guilty to manslaughter Friday in the death of their father, who prosecutors say was stricken after a violent clash with his son. Prosecutors say 70-year-old Daniel Kerrigan died after the fight with 45-year-old Mark Kerrigan in the family home in Stoneham, outside Boston.

The family says Mark Kerrigan is not responsible for his father's death. Kerrigan was arraigned in Middlesex Superior Court in Woburn, where he entered not guilty pleas to manslaughter and assault. He left the courthouse without comment just before noon after posting a new $25,000 bail set by the clerk magistrate.

"The Kerrigans are extremely pleased to have Mark back at home where he belongs," his family said later in a statement. Before the manslaughter indictment, Kerrigan had been out on bail and living with his mother in the family's Stoneham home, where the alleged assault took place.

Prosecutors said Kerrigan was in a drunken rage during a Jan. 24 argument with his father over the use of the family telephone when the conflict escalated into violence. Officials said the younger Kerrigan began grabbing and shoving his father. They said Kerrigan grabbed his father around the neck, fracturing his larynx and causing him to fall to the floor on his back, unconscious.

A state medical examiner said the cause of death was "cardiac dysrhythmia" - a loss or interruption of a normal heartbeat that can lead to cardiac arrest - after an altercation with neck compression that damaged his windpipe. The findings also noted that the elder Kerrigan had high blood pressure and clogged arteries.

On Friday, prosecutor Elizabeth Keeley argued for $50,000 bail, saying Mark Kerrigan has a history of violence and had been released from a 3 1/2-year prison term only two months before the fight with his father. Keeley said Kerrigan suffers from anxiety over his fear of returning to prison, and told police he would resist if they came to arrest him again.

She noted his mother, Brenda Kerrigan, who is legally blind, was the only witness to the fight. "I would suggest ... that this defendant is a risk to his mother," Keeley said. Defense attorney Janice Bassil countered that it is "simply absurd" to suggest Kerrigan is a threat to his mother and called the prosecutor's statements "a blatant attempt to poison public opinion about Mr. Kerrigan."

Bassil said Kerrigan has complied with the bail conditions. She said his earlier remarks about police came when he was intoxicated and that he is forbidden from drinking as a condition of his bail. Bassil said the family wants Mark Kerrigan home as they continue to deal with Daniel Kerrigan's death. "Mark grieves, as well, and it is just simply unfair to try to pit him against his family," Bassil said.

Prosecutors have mischaracterized medical evidence by saying that Daniel Kerrigan had a fractured larynx as a result of the fight with his son, Bassil said. She said the fracture was in a section of the larynx, the left thyroid cartilage, far from the fragile bone of the larynx usually broken during strangulation and could have been the result a pre-existing injury. She blamed Daniel Kerrigan's death on a long-standing heart condition.

"The fact is Mr. Kerrigan died, unfortunately, of a series of heart problems," Bassil said. Members of the Kerrigan family say they don't blame Mark Kerrigan for the death and the family's attorney, Robert Delahunt Jr., repeated that Friday. "The Kerrigan family is united in their support of Mark Kerrigan and belief of his innocence," he said. He also said Mark plays a vital role in his mother's ability to live independently.

In announcing the indictment Thursday, Middlesex District Attorney Gerry Leone said Mark Kerrigan's "reckless actions and complete disregard for his father's safety and well-being" led to his death. Mark Kerrigan has a criminal record, with convictions dating to 1991, including drunken driving, assault and battery, domestic assaults, resisting arrest and violation of a restraining order.

His former lawyer said Kerrigan, an unemployed plumber, was on medication for post-traumatic stress disorder from military service and was seeing a psychiatrist. Nancy Kerrigan, of Lynnfield, won the bronze medal at the 1992 Olympics in Albertville, France, and the silver at the 1994 Winter Olympics in Lillehammer, Norway. She won a gold medal at the 1993 U.S. Championships. She was at the center of a saga at the U.S. Championships before the 1994 Games, when an assailant clubbed her right knee during practice and an investigation revealed rival Tonya Harding had knowledge of the planning of the attack.