OCILLA, Ga. (AP) — A jury on Friday found a man accused of killing a popular high school teacher who vanished from her rural Georgia hometown in 2005 not guilty of murder.

Ryan Duke had told investigators he killed Tara Grinstead and helped burn her body. But when he took the witness stand during his trial, he insisted he was innocent.

The jury acquitted Duke of malice murder, felony murder, aggravated assault and burglary but found him guilty of concealing a death, The Atlanta Journal-Constitution reported.

Grinstead’s disappearance in rural Irwin County remained a mystery for more than a decade until Duke’s 2017 confession.

He told Georgia Bureau of Investigation agents that he broke into Grinstead’s home in October 2005 hoping to find money to steal to buy drugs. He was startled when Grinstead appeared behind him and he hit and killed her, he said.

Duke led investigators to a pecan orchard where he said he and a friend, Bo Dukes, burned her body. GBI agents testified at trial that Duke knew things about the case that had never been made public.

Duke’s defense attorney, John Merchant, told jurors it was Dukes who killed Grinstead. Dukes was convicted in 2019 of helping move and burn Grinstead’s body but was never charged with murder.

Duke testified that his confession was false. He said Dukes woke him up at the mobile home where they lived together in 2005 and said he had killed Grinstead and showed Duke the teacher’s purse and wallet. Duke lied to investigators because Dukes had already killed one person and he was afraid, he testified.

Duke’s murder trial opened last week, more than 16 years after Grinstead was last seen leaving an evening cookout in rural south Georgia. Grinstead, who taught history and was a former beauty queen, was just 30 when she disappeared.

Before Duke’s confession, her family held out hope that she might return home safe.

Though her body was never found, investigators matched Grinstead’s DNA to bone fragments recovered in the area where Duke told investigators he and his friend had burned her.

The jury deliberated Thursday afternoon and for about two hours Friday morning before delivering a verdict, the Journal-Constitution reported.

Duke is to be sentenced Monday. Grinstead’s family asked for more time to prepare statements to read at the sentencing.