Two Haralson County men have been arrested and charged with killing an 80-year-old man who was robbed, bound with duct tape, beaten and shot to death in his home over the weekend, authorities said.

“Anyone who could commit a crime like this, especially against a senior, is despicable,” Haralson County Sheriff Eddie Mixon said.

Updating earlier reports that Ophir Lee Thompson had been clubbed to death, the Georgia Bureau of Investigation said Monday night that an autopsy performed at the GBI Crime Lab in Decatur determined the man died of gunshot wounds to the head.

"Thompson had other injuries which were also associated with this death," the GBI said in a news release. The agency is working with Haralson County Sheriff's Department to investigate the incident.

A Haralson County Sheriff’s deputy found Thompson dead in his home in the 7900 block of Ga. 120 about 10 p.m. Saturday, authorities said. The deputy was checking on the man at the request of a relative who had been trying to reach him by phone that day.

The deputy found glass inside the home, indicating a break-in, and Thompson lying on the floor as well as several live bullet rounds on the floor and a ledge.

Deputy Jim Beck, spokesman for the Haralson Sheriff's office, said that firearms and a large amount of cash had been taken from a safe in a bedroom, along with horse tack, including two saddles.

It was known in the community that Thompson kept cash in his home, the sheriff’s deputy said. Some of the money has been recovered, he said.

A piece of clothing left at the scene led investigators to Ronnie Duane Lewis, 29, who had lived with the victim previously, Beck said. Also, an acquaintance of Lewis told authorities he had allegedly been approached by the man and asked to store guns and other property.

“Investigators believe that after tying Mr. Thompson with duct tape, Ronnie Lewis beat his elderly victim to force Ophir Thompson to reveal the combination to his safe,” Beck said.

Lewis, a resident of Bremen, was picked up in a camper in Buchanan where he had been staying.

Further inquiries led investigators to the Tallapoosa home of Mickey Ray Mulder Jr., 26, an associate of Lewis and a suspected accomplice, Beck said. After speaking with Lewis and Mulder, deputies recovered the shotgun they said was used to beat Thompson.

It was unclear Monday night if the same firearm was used to kill him.

Lewis has been charged with murder, armed robbery, false imprisonment, aggravated battery on an elderly person, aggravated assault, and theft by taking firearms, as well as felony theft by taking. Mauler was with charged with theft by receiving and being a party to crime.

Both men are being held in the Haralson County Jail.