A 28-year-old Tucson man, who was once facing a potential death sentence, will serve 31 years in prison instead for the brutal death of a retired landscape architect for Pima County.

Jonathan Baumbach pleaded guilty to second-degree murder and kidnapping in the June 2011 death of Robert Pardee, 61.

Court documents and testimony indicate Pardee was killed because he became tired of Baumbach and Baumbach's lover using his home to party.

Baumbach admitted he told Pardee he was going to give him a present, blindfolded him and then hit him in the head with a hammer repeatedly.

Baumbach left the home, but when he returned he found Pardee had dragged himself into the bathroom, Kellie Johnson, chief criminal deputy county attorney, told Judge Richard Fields Monday. So he struck Pardee with the hammer several more times and slit his throat before stealing his credit cards, truck and other personal belongings, Johnson said.

Baumbach and his boyfriend partied in Las Vegas for a couple of days before continuing to Washington, where he was found sleeping in the back of Pardee's truck.

Pardee's body wasn't found for 11 days, until after his daughter asked Tucson police to check on him because she hadn't heard from him in a while.

Johnson said Baumbach was given a plea agreement to spare the victim's daughter the trauma of a trial.

Assistant Pima County Legal Defender Alicia Cata asked Fields to impose a shorter sentence, saying her client was abused and abandoned as a child by his mother, has mental health issues and a damaged frontal lobe.

Baumbach is remorseful and accepts responsibility for his actions, Cata said.

Pardee's family told the judge Pardee was the youngest of five children, a devoted father and former suicide hotline volunteer who took part in designing Agua Caliente Park and participated in the creation of Feliz Paseos Park, which is distinctive for its paved trail to afford access to the disabled.

Fighting back tears, Pardee's brother, Gordon, said no words could describe the magnitude of the trauma Baumbach inflicted on their family.