A Georgia man was charged Monday with the murder of his girlfriend, a University of Georgia professor, who was found fatally strangled next to the hot tub at a friend’s home. That friend later killed himself after being questioned by investigators.

Authorities believe Marcus Lillard, 41, strangled 43-year-old Dr. Marianne Clopton Shockley late Saturday night while they visited their friend Sydney Clark Heindel. When the two men were split up for questioning, Heindel allegedly went inside the house and took his own life, though authorities did not elaborate on his motive.

Lillard was subsequently charged with murder, concealing a death, and aggravated assault, a police spokesman confirmed to The Daily Beast, clarifying that none of the charges are related to Heindel’s death.

“It’s one of the strangest cases that we’ve ever worked,” Baldwin County Sheriff Bill Massee said in a press conference on Monday. “I don’t know how to explain this to people who are not in our business, but when we first arrived at the crime scene, there was something about it that was not right, and it was just kind of a bizarre, different kind of case."

Investigators believe Shockley had been dead for about two hours before police responded to reports of a drowning at the Milledgeville, Georgia, home at 1 .a.m., citing text conversations from Lillard to friends asking if they knew how to perform CPR.

“The concealing charge of the death occurs from Mr. Lillard making calls two hours prior to the 911 call requesting people to help him, tell him how to get somebody back to life, how to help someone do CPR, basically how to help save a life,” Massee said.

When police arrived, three people were still naked and Heindel, a 69-year-old clinical psychologist, was still attempting to perform CPR on Shockley, who was lying by the tub with a heavily bleeding head wound.

Shockley, who since 2001 was an entomology professor at UGA’s College of Agricultural and Environmental Sciences, was pronounced dead at the scene. Preliminary autopsy results revealed that she died by strangulation.

Lillard told authorities that after coming back from getting wood for a firepit, he noticed Shockley was “passed out” in the hot tub, according the police report. After he pulled his girlfriend out of the tub, Lillard said, he jumped “in the pool” to swim her to the other side but fell on the deck, where Shockley hit her head on impact.

“It had been raining heavily earlier in the day so it seemed odd that Lillard would be trying to make a fire with everything being wet,” one deputy noted in the police report. “There was also a large pile of firewood already placed beside the fire pit near the pool.”

Heindel told authorities that he was swimming on the end of the pool when Lillard found Shockley. According to the police report, Heindel claimed that when the two men performed CPR on Shockley, she “appeared to be breathing faintly so they assumed she was coming back into consciousness and did not immediately call 911.”

Investigators then decided to split up the men for questioning after noticing a blood-soaked patch of grass near the hot tub and analyzing the severity of Shockley’s head injury. They brought Lillard into a patrol car while Heindel was moved to the front porch.

While the deputies questioned Lillard, Heindel went inside the house and shot himself in his master bathroom, Massee said. His death was ruled a suicide and authorities do not believe he played a role in the professor’s death.

“This is pure speculation on my part, but maybe he was embarrassed that this happened at his house,” Massee said, adding that the suicide is not being considered evidence of guilt.

It is not immediately clear how long the trio have known each other, but investigators believe Lillard, a former car salesman, and Heindel knew each other for about four years. Lillard and Shockley are believed to have just begun dating, but authorities declined to elaborate or speculate on motive.

“On behalf of the university, I’d like to express our deepest sympathy to the family, students and colleagues of Dr. Marianne Shockley,” a school spokesman told The Daily Beast on Tuesday.

The Georgia Bureau of Investigation confirmed to The Daily Beast that they are assisting Baldwin County Sheriff’s Office with the probe, but declined to comment. Lillard was initially arrested at the scene for a state probation violation and is currently being held without bail at the Baldwin County Detention Center.