An Arizona man who served 37 years in prison for two murders was arrested in Colorado in October for allegedly sexually assaulting a young female relative.

The Arizona Republic first reported the new charges against William Macumber on Tuesday and said he was free for less than a year before the new arrest.

Macumber, 78, was arrested on Oct. 7, and charged with four counts of sexual assault of a child, the report said. His ex-wife, Carol Kempfert, informed the paper of the new arrest. Macumber, who says he did not commit the murders for which he served time, also denies the new charges, an attorney who worked to free him in 2012, told the paper.

He was reportedly staying in Colorado with his son, Ronald, who confronted his father about the allegations, the report said. Ronald Macumber kicked his father out of the house after hearing his response, the report said.

Authorities were alerted to the allegations after a family member, who works as a sheriff's deputy, heard about the allegations and, under state law, had to report them.

Macumber was convicted of first-degree murder in 1975, more than a decade after the 1962 killings of 20-year-olds Joyce Sterrenberg and Timothy McKillop. He pleaded no contest in November  2012  to second-degree murder and was sentenced to time already served. The plea resulted from a deal struck with prosecutors as Macumber's lawyers pressed for a new trial based on claims that he was innocent.

Relatives of the victims objected to Macumber's release, saying they still considered him guilty.

"It makes me angry to no end, for the 12 years I spent to get him out of jail, to do what he did," Ronald Macumber, reportedly said. "When he's found guilty, he can rot in prison. He's lost everything as far as I'm concerned."

William Macumber is being held in Colorado and faces a minimum of four years in prison if convicted. 

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