— -- Mark Kerrigan did not cause his father's death. That was the message from a Massachusetts jury today that found Kerrigan not guilty of killing his father during a violent argument in the family's home on the night of Jan. 25, 2010.

The jury did convict Kerrigan of a separate charge of assault and battery – a crime that carries a possible sentence of 2.5 years.

Kerrigan's famous sister, 41-year-old Olympic skater Nancy Kerrigan, began to cry as her brother Mark entered the courtroom to hear his fate this morning. She spoke to reporters briefly after the verdict was read. "My family has never believed that my brother had anything to do with my father's death."

But prosecutors contended Mark Kerrigan – who has a long history of substance abuse and run-ins with the law - was enraged and drunk the night of 70-year-old Daniel Kerrigan's death.

The two had been arguing about whether or not Mark could use the phone that night. Prosecutors said that during the argument Mark Kerrigan grabbed his father around the neck, causing cartilage in his larynx to tear and triggering a cardiac event that lead to Daniel Kerrigan's death.

During the six-day trial, defense attorneys countered that Daniel Kerrigan's death was caused by his history of heart problems and had nothing to do with Mark Kerrigan's actions that night. Janice Bassil, one of Kerrigan's defense attorneys', said, "This was an enormous ordeal for the family. Are they relieved that this is almost over? Yes."

Nancy and Brenda Kerrigan, Daniel Kerrigan's wife, have steadfastly stood by Mark Kerrigan since the incident occurred. During the six-day trial, mother and daughter sat next to each other as they listened to the often painful testimony.

A 911 tape of the night was played for the jury in which Brenda Kerrigan could be heard yelling for her son, Mark, to get away from her husband.

In court, assistant district attorney Elizabeth Keeley said, "Daniel Kerrigan spent the last few minutes of his conscious life fending off his drunk 45-year-old son."

American Skating Royalty

The Kerrigan family has been a part of American skating royalty since the early 1990s. Nancy Kerrigan won a bronze medal at the 1992 Olympics in Albertville, France. But it was the dramatic attack on the young skater in 1994 that made the Stoneham, Mass., native a household name. An assailant struck Nancy Kerrigan in the knee with a lead pipe before an upcoming competition, and the video of her father picking up his daughter and carrying her off as she screamed in pain captured the nation's hearts.

Nancy Kerrigan went on to win a silver medal at the 1994 Olympics in Lillehammer, Norway.

While Nancy Kerrigan found fame, her older brother foundered.

Mark Kerrigan has served time in jail on various charges including assault. At one point, Daniel and Brenda Kerrigan even sued their son, according to court documents obtained by the Boston Herald, claiming he owed them thousands of dollars that he refused to pay back. The money was to cover his living expenses over several years, and the list included $31,870 in mortgage payments, $1, 336 for heating oil and $197 for cat food. The lawsuit was eventually dismissed.

And then on Jan. 25, 2010, Brenda Kerrigan called 911 to report that her husband had fallen. The 911 operator – hearing a commotion - asked whether there was fighting in the background and Brenda Kerrigan said, "Oh, yes." Mark Kerrigan took the phone and told the operator his father "seemed to have a heart attack."

Daniel Kerrigan was pronounced dead at Winchester Hospital a short time later.

The prosecutors initially charged Kerrigan with assault but upgraded the charges a short time later. When asked today if they overreached in charging Mark Kerrigan with involuntary manslaughter, DA Gerald T. Leone Jr. said "I know we charged this case right … under the facts, under the law." And, Leone added, "Daniel Kerrigan wouldn't be dead if not for the actions of Mark, an angry, belligerent, intoxicated 45-year-old man."

The messy family history has left many scratching their heads, wondering why Brenda and Nancy Kerrigan would remain so supportive of Mark Kerrigan given the events of that night and his history. The two women have always maintained that they loved Mark Kerrigan and did not hold him responsible for his father's death.

And during the trial Janice Bassil, Kerrigan's defense attorney, said simply that her client loved his father.

Tomorrow Mark Kerrigan will be back in court to hear his sentence on the assault-and-battery.

Ashleigh Banfield and Taylor Behrendt contributed to this story.