A University of Georgia professor was strangled to death by her boyfriend Saturday night at the home of a Milledgeville man who subsequently committed suicide, according to Baldwin County Sheriff Bill Massee.

Massee said the alleged murder of 43-year-old Marianne Clopton Shockley of Madison was one of the "strangest" cases his agency had ever investigated.

Shockley was an entomology professor with UGA’s College of Agricultural and Environmental Sciences.

Her boyfriend, 41-year-old Marcus Allen Lillard of Milledgeville was charged with murder, aggravated assault and concealing the death of another, the sheriff said.

Authorities learned about the incident just after 1 a.m. Sunday, when 69-year-old Sydney Clark Heindel, also of Milledgeville, called 911 to report that Shockley had drowned in a hot tub at his home.

When deputies arrived they found Heindel and Lillard attempting to perform CPR on Shockley on the deck of Heindel’s pool, according to an incident report from the Baldwin County Sheriff’s Office. The report noted that all three people were nude.

Although both men said Shockley had drowned in the hot tub, there were peculiarities about the men’s demeanors and evidence at the scene that cast doubt on their version of events, Massee said.

"It was just the totality of circumstances that made it seem that this wasn't a simple case of drowning," the sheriff said.

Among other things, Shockley was bleeding heavily from a head injury and her eyeglasses and a bracelet were found near some blood-soaked grass away from the hot tub, according to an incident report released by the sheriff’s office.

Lillard explained the head injury by saying that after he pulled Shockley from the hot tub he fell on the pool’s deck while carrying her, according to the report.

Lillard also stated he found Shockley unresponsive in the hot tub after he returned from a wooded area where he gathered wood for a fire pit, the report noted.

“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,” a deputy wrote in the incident report.

“There was also a large pile of firewood already placed beside the fire pit near the pool,” the deputy noted in the report.

Heindel stated that he was swimming on the on the end of the pool away from the deck when Lillard found Shockley unresponsive in the hot tub, according to the incident report.

The report noted that Heindel stated when he and Lillard performed CPR Shockley “appeared to be breathing faintly so they assumed she was coming back into consciousness and did not immediately call 911,” the report noted, adding that Heindel called 911 about 45 minutes later.

According to Massee, investigators later determined that Lillard began texting friends at 11:15 p.m. Saturday — about two hours before Heindel called 911 — asking if any of them knew how to perform CPR.

Shockley was dead when deputies arrived, according to the incident report.

When deputies realized that Shockley’s death might not have been an accident they separated the two men so that they could be questioned individually by detectives, according to the report. Lillard reportedly sat in a patrol car while Heindel sat on the front porch.

When a deputy coroner asked the deputies if they had located Shockley’s driver’s license, the deputies went to ask Heindel if they knew where the woman’s purse was, but the man was no longer on the porch, according to the report.

When a deputy knocked on the front door and called out Heindel’s name, he heard a gunshot from inside the residence and subsequently located Heindel in the master bedroom, dead from an apparent self-inflicted shotgun wound to the head, according to the report.

The Georgia bureau of Investigation was asked by the Baldwin County Sheriff’s Office to assist in the investigation.

Preliminary autopsy results revealed that Shockley died from being strangled and Heindel’s death was ruled a suicide, Massee said.

According to the sheriff, a motive for Lillard killing Shockley was not known and the man made no admissions to investigators.

Massee said it was not believed that Heindel played a role in the UGA professor’s death, and that his suicide was not evidence of guilt.

“This is pure speculation on my part, but maybe he was embarrassed that this happened at his house,” the sheriff said.

Lillard was arrested at the scene for a state probation violation and a GBI agent Monday afternoon took out warrants charging Lillard with Shockley’s death. He was being held without bail at the Baldwin County detention Center.