The autopsy on Shockley showed she died of strangulation, the sheriff said, adding that Lillard is believed to be the killer.

Marianne Shockley was found dead on Mother’s Day. Police believe her boyfriend killed her.

The news has devastated and confounded Shockley’s family and is especially hard for her teen children, who lost their mother on Mother’s Day, said the professor’s friend Terry Jenkins. If only for the kids’ sake, Jenkins said he hoped people will try to focus on the person Shockley was, not just the strange circumstances of her death. He described Shockley as a grounded yet driven free spirit who cherished family and her work and research.

“You’re just as likely to find her in the Galapagos Islands as you are the church from her childhood,” Jenkins told The Atlanta Journal-Constitution. “I don’t think the church is going to be able to hold the amount of people that are going to come to her service.”

Investigators aren’t sure how long Shockley had been dating Lillard, but they believe the relationship was somewhat short-lived. Jenkins thought the same.

The sheriff said Lillard spent two hours trying to revive Shockley before Heindel finally called 911. The motive is unknown. Lillard, for his part, denied harming his girlfriend. He said her head wound came from when he bumped it while pulling her from the hot tub to try to revive her, according to the report.

The sheriff said investigators haven’t pieced the case together yet.

“We can’t really document exactly what happened,” Massee said. “We do know from the phone calls and all that they had reached out to several people, had sent out group texts to try to get help.”

UGA spokesman Greg Trevor said Shockley was an academic professional associate in the Department of Entomology with the College of Agriculture and Environmental Sciences. In a statement, he said, in part: "I'd like to express our deepest sympathy to the family, students and colleagues of Dr. Marianne Shockley."

Lillard is jailed on charges of murder, concealing a death and aggravated assault.

The sheriff called the case terribly sad and one of the strangest he’s worked.

A GoFundMe page set up to help with funeral costs for Shockley. A memorial service will be held at 2 p.m. Friday at Apalachee United Methodist Church at 5070 Lower Apalachee Road in Madison.

A family member told the AJC relatives didn’t want to comment Tuesday.