SANTA ROSA -- A Chico man was sentenced to life in prison without paroleTuesday morning for killing his grandfather for financial gain nearly two years ago.

Sonoma County Superior Court Judge Kenneth Gnoss also sentenced Sean Patrick Mooney to a consecutive 25-years-to-life term for intentionally discharging a firearm causing great bodily injury.

Mooney, 22, was convicted of shooting his 77-year-old grandfather, Robert Deming, with a shotgun in the back of the head at point-blank range inside his Schellville home near Sonoma on May 20, 2008.

Deputy District Attorney Traci Carrillo argued during the trial that Mooney knew he would benefit financially from Deming's death because his mother would inherit Deming's property and Mooney would receive half of his mother's inheritance.

Mooney wanted to live in a camper on Deming's property and he was aware that his grandfather had a life insurance policy, Carrillo said.

When the jury convicted him on July 24, Mooney cried out, saying he had simply needed a home. He said of his mother, "She wouldn't give me anywhere to live. I needed a house, not money."

Mooney's parents planned to sell the Chico house where Mooney and his girlfriend were living, Carrillo said.

Mooney initially told Sonoma County sheriff's investigators that two intruders had killed his grandfather. He later told his mother he was holding the 12-gauge shotgun to prevent his grandfather from committing suicide and that it fired by accident.

Members of Mooney's family spoke at the sentencing.

"There have been many differences in this family over the years and this case has not changed that," said Carolyn Deming, Mooney's aunt and Robert Deming's daughter.

"We feel that this is not the right result," she said of the conviction.

Deming's son David used expletives to berate Mooney, who looked straight ahead during the hearing, and called the killing an assassination.

"There's a lot of things I'd like to do to his ass right here," Deming said before Gnoss admonished him.

Deming's nephew Mark Deming said his uncle was "a beautiful person" and "the great man of the family."

"My uncle was always there for us," he said. "He was a health fanatic. The last words he spoke to me were about green leafy vegetables. To have his life snuffed out by this cockroach makes me sick," he said.

Mark Deming said all the members of his divided family will be dead before Mooney dies in prison.

"They will sweep up his ashes and put them in the garbage," he said.

Mooney was convicted of first-degree murder for financial gain, weapons enhancements, elder abuse and receiving stolen property, the shotgun. His attorney John Halley said Mooney is appealing his conviction.

"We still dispute the result of this case. There are genuine, substantial legal issues on appeal," Halley said.