A confession and tip last month from a death row inmate just before his execution led investigators to the body of Felicia Cox, the convicted man’s sister-in-law.

David Neal Cox was put to death in Mississippi on November 17 after he halted all appeals of his conviction for the murder of his wife, Kim Kirk Cox, and sexual assault of his stepdaughter in 2010.

Before his execution, he told his lawyers he had killed his brother’s wife in 2007 and detailed the location of her body in a letter he asked not to be opened until he was dead, as CrimeOnline previously reported.

Earlier this month, investigators found the remains of a woman on land once owned by the family, and on Wednesday, First Circuit District Attorney John Weddle said the remains had been positively identified as 40-year-old Felicia Cox.

“We expect autopsy results within two weeks,” Weddle said in a Facebook post.

Authorities had long suspected David Cox had a hand in his sister-in-law’s death but never compiled enough evidence to charge him.

He was later convicted of killing his wife and sexually assaulting his stepdaughter as her mother lay dying. He eventually told his attorneys to stop appealing the conviction and told the Mississippi Supreme Court that he felt he was “worthy of death.”

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[Feature Photo: Felicia Cox/Family Handout; David Cox/Handout]