A 60-year-old man admitted to sheriff's deputies that he beat his girlfriend to death in the central Minnesota home they shared, according to murder charges filed Tuesday.

Harold A. Wassather of Motley was charged in Morrison County District Court with second- and third-degree murder in connection with the death of 66-year-old Christine Nygard at a home in the 600 block of S. Hwy. 10.

Wassather told law enforcement after his arrest outside the home that he beat Nygard "after she accused him of talking to other women," the charges read.

He also admitted to having assaulted Nygard in the past, but law enforcement was never notified, the criminal complaint read.

"Our thoughts and prayers go out to the victim's family for this senseless act of violence and to the First Responders that investigated and processed the scene," Sheriff Shawn Larsen said in a statement. "The victim tragically lost her life to domestic violence, which could have been prevented."

Wassather remains jailed in lieu of $500,000 bail. A message seeking a response to the allegations was left with his attorney.

According to the complaint:

A caller from Minneapolis alerted the Sheriff's Office on Sunday to Nygard's death. Officers found her body on a bed, her face "covered in dark bruises, indicating possible head trauma," the charges read.

Under questioning in jail, Wassather cried as he said he didn't mean to kill her. He said that after the assault, he put his unconscious girlfriend in bed and covered her up.

Wassather said he didn't call 911 or tell anyone what happened until he told a friend. He said the attack could have happened as far back as March 2, but he was uncertain "because he kind of lost track of time," the complaint read.