A 37-year-old South Carolina man has been arrested and charged with the murder of his mother last December.

The Lexington County Sheriff’s Office said Terry Lee Self Jr. used a ligature to strangle Regina Arroyo and then dumped her body into the Edisto River.

“A canoer found the body of the suspect’s mother in the Edisto River December 3,” Lexington County Sheriff Jay Koon said. “Detectives confirmed the suspect and his mother were at the suspects house and left there together after an argument.”

Self is currently behind bars in Richland County on an unrelated charge. He was denied bond in the Lexington County case on Monday.

Arroyo, 56, was reported missing on November 30, WIS reported.

Missy Chrysler, Lee’s sister, told the station her brother had showed a marked personality change in recent months that alarmed the family.

“I didn’t want to believe it though, like, who would kill their mother, you know, like my brother wouldn’t have done that,” she said. “But I denied it, up until an investigator … told me he had done it.”

Chrysler said her mother “was always there for him,” including “the first time he went to prison in New York state.”

Lexington County officials said he’d been booked into jail there six times since 2016.

“My mom would always do for him, no matter what he did, she forgave him, and tried to help him the best that she could, ‘he is my son, what am I to do?'” Chrysler said.

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[Featured image: Regina Arroyo/GoFundMe. Inset: Terry Lee Self Jr/Lexington County Sheriff’s Office]