A car salesman was charged Monday in the strangulation death of a University of Georgia professor who was found dead near a hot tub at the home of a man who killed himself after police arrived at the scene.

Marcus Lillard faces charges of murder, concealing a death and aggravated assault, Baldwin County Sheriff Bill Massee said during a news conference Monday. Police believe he strangled Marianne Clopton Shockley late Saturday night while they were visiting the home of Sydney Clark Heindel.

Police received a report of a drowning at the home at about 1 a.m. Sunday, Massee said.

Marcus Lillard was arrested in connection to a murder of a University of Georgia professor on May 13, 2019. Baldwin County Sheriff's Office

When officers arrived at the home in Milledgeville, southeast of Atlanta, "they decided that the scene looked a little inappropriate" based on "the demeanor of the people at the scene," and "there was some blood," Massee said.

After placing Lillard in a patrol car, officers told Heindel that he would be separated from Lillard and interviewed, Massee said. Then they left him alone.

Heindel then went into his house and shot himself in his master bathroom, Massee said.

"It’s one of the strangest cases that we’ve ever worked," Massee added. "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 were called because they have records of Lillard calling people Saturday night and asking them how to perform CPR and "basically how to save a life," Massee said.

Investigators believe Lillard and Heindel had known each other for about four years. It's unclear how long Lillard and Shockley knew one another, but they arrived at Heindel's house in the same car Saturday night, Massee said.

Heindel was once a clinical psychologist, but was no longer licensed, and owned a yoga studio, while Lillard was a car salesman who had recently quit his job, Massee said.

Shockley's faculty profile says she had a doctorate in entomology and had worked at the University of Georgia since 2001.

"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 said.