A registered sex offender has been accused of killing his ex-wife after remains believed to be hers were found on his property.

Charles Michael Patrick was arrested Thursday in the disappearance of Drusilla Patrick, according to the GBI. He was charged with murder.

An autopsy was performed Friday.

“The cause of death was determined to be gunshot wound and the manner of death was determined to be homicide,” GBI spokeswoman Nelly Miles said in a statement. “A formal forensic identification of Drusilla Patrick is pending.”

The remains were discovered after a probation official supervising Charles Patrick became concerned about the woman’s whereabouts and notified the Gilmer County Sheriff’s Office.

At that point, the GBI was called in to assist with the investigation.

Drusilla Patrick, 68, was last seen alive between December 2016 and January 2017, according to the GBI. Charles Patrick, 72, who was remarried, gave conflicting statements about the whereabouts of his former wife, Miles said.

The Patricks divorced in 1970, authorities said.

“The investigation further revealed that Charles Patrick had given a variety of reasons for Drusilla Patrick’s absence to several different people, each contradictory to the other,” Miles said.

Officials executed a search warrant of Charles Patrick’s home Wednesday and continued searching the property Thursday. That’s when they found the remains.

Patrick is being held at the Gilmer County Detention Center, Miles said.

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