A man who admitted bludgeoning his father to death was sentenced to 20 years in prison Wednesday, despite pleas for leniency from relatives who said the father had abused his entire family for years.

Mulumba Kazigo, 26, sat stoically as Nassau County Court Judge William Donnino read the sentence. He pleaded guilty last month to first-degree manslaughter.

"If I could do this all over again and give his life back, I would," said Kazigo, sitting in handcuffs at the defense table for the sentencing. "But I cannot change what happened on that morning."

Kazigo declined to withdraw his guilty plea in the August 2004 slaying of his father, Dr. Joseph Kazigo, who moved to the United States from Uganda 40 years ago. If convicted at trial, Mulumba Kazigo could have faced 25 years to life in prison. Twenty years was the maximum under his plea deal.

He admitted that he broke into Long Island apartment that his 67-year-old father used while working in the emergency room at the Nassau County Medical Center, beat him with a baseball bat and slit his throat. He then wrapped the body with plastic bags and duct tape and dumped it in a wooded area.

Attorney Steven Chaikin said Mulumba Kazigo was mentally ill. His mother, one brother and a sister all wrote to Prosecutor Kathleen Rice, pleading for a term of less than 20 years.

"In my wildest dreams I never imagined my brother would ... put an end to my mother's beatings the only way he knew would be effective," Nakizito Kazigo, an Army doctor in Afghanistan, wrote in a plea for leniency for her brother.

Rice, elected last November after criticizing plea bargains by her predecessor, said Mulumba Kazigo's actions reflected premeditation.

"This is a heinous, heinous murder," she said. "The victim was not only viciously beaten with a baseball bat as he slept, his throat was slit."

Rice added that the family history of abuse was a mitigating factor, but "it does not obviate the need for serious punishment."