CLEVELAND, Miss. — The university professor accused of killing his girlfriend and a colleague was a well-liked teacher, a musician and a father, but also someone who had medical problems and recently asked for a leave of absence from teaching.

Authorities worked Tuesday to figure out how the three lives intersected and what set off geography professor Shannon Lamb, who killed himself as police closed in on him during a manhunt.

Lamb is suspected of first killing his girlfriend Amy Prentiss, 41, in a home they shared in the coastal town of Gautier. Lamb then drove more than 300 miles north to Delta State University, where he is accused of fatally shooting 39-year-old Ethan Schmidt, a history professor who was killed in his campus office.

Police have not released a motive for the shooting. University President William LaForge said he didn’t know of any conflict between Lamb and Schmidt but “obviously there was something in Mr. Lamb’s mind.”

Lamb had earlier asked for a medical leave of absence, saying he had a health issue of some sort, but LaForge gave no further information about it.

The shooting led to an hours-long lockdown at the college during which frightened students and faculty hid in classrooms and closets as authorities scoured the campus looking for Lamb. The campus was eventually cleared by police and authorities later found Lamb when a license plate reader picked up his plate as he crossed a bridge over the Mississippi River from Arkansas back into Mississippi, Cleveland police Chief Charles “Buster” Bingham said.

Police followed Lamb but did not try to apprehend him. He pulled down a driveway north of Greenville, near his parents’ home and ran into the woods. As police were waiting for backup, he shot himself in the head.

Lamb started working at the university in 2009 and taught geography and education classes. He received a doctorate in education in the spring. He was teaching two online classes this semester, but an in-person class had been cancelled, LaForge said.

Lamb’s career prospects at Delta State may have taken a turn because of a university policy change.

After LaForge became president, he hired a new provost, Charles McAdams, who ended a prior university practice whereby an instructor who earned a doctorate could automatically join the tenure track and become an assistant professor. LaForge said that practice violated state policy which requires an open search for new professor positions.

Brandon Beavers, an education major, said he had a class with Lamb last year.

“It was like that class you look forward to,” Beavers said. “It was just cool.”

However, he said Lamb seemed agitated.

“He was really jittery, like there was something wrong with him,” Beavers said. “He was never in a bad mood, but he was real shaky.”

One of Lamb’s longtime friends described him Tuesday as smart, charismatic and funny. Hairston and Lamb both grew up in Greenville, Mississippi.

Carla Hairston said she was 15 and Lamb was 20 when they met through mutual friends. She and her friends were in high school, and he was the cool older guy who tried for several years to teach her to play guitar. He was a good teacher but she was an uncoordinated student, she said.

“He was quite the heartthrob back then. All the girls would melt when he was around,” said Hairston, now 40 and living in the Jackson suburb of Brandon.

“He had the Elvis effect,” Hairston said. “His voice was just like velvet, and people just loved to hear him talk.”

Hairston said even when she wanted to be a rebellious teen and stay out late, Lamb made sure she and her friends went home by curfew. She said he was whip smart and would often quote song lyrics in conversation.

“He made corny and dorky look good,” Hairston said.

Lamb and Prentiss had apparently been dating for some time. Prentiss’ ex-husband said they divorced 15 years ago but remained friends and had a daughter who’s now 19.

“She was completely devastated,” she said of his daughter. “She and her mother were absolutely best friends.”

Schmidt, the slain professor, directed the first-year seminar program and specialized in Native American and colonial history, said Don Allan Mitchell, an English professor at the school.

Karen Manners Smith was a history professor at Emporia State University in Kansas, where Schmidt studied.

“He was a super competent human being,” Smith said. “He was president of his fraternity, in student government. He was an absolutely delightful student.”

At the campus of 3,500 students, the police blockades had been removed, people were out cutting the grass and traffic moved normally, although there was not a lot of pedestrian traffic.

More than 70 students, faculty and staff attended counseling sessions at Delta State, according to Dr. Richard Houston, the university’s director of counseling. And the school had planned to celebrate its 90th anniversary Tuesday — some of the festivities were even supposed to be in Jobe Hall where the shooting happened — but LaForge said that event will be rescheduled.

A vigil was planned for Tuesday night and classes resume Wednesday.

“We’re trying to get our students to come back,” LaForge said. “The crisis is over. This is a day of healing.”

Emily Wagster Pettus in Jackson, Mississippi; Kevin McGill in Gautier, Mississippi; Rebecca Santana in New Orleans; and Roxana Hegeman in Wichita, Kansas, contributed to this report.