Who was Delta State University shooting suspect Shannon Lamb?

(CNN)A profile of Shannon Lamb on his university's website described him as an expert on the geography of crime.

Authorities say he was the suspect in two homicides who led them on a daylong manhunt before killing himself.

Lamb was accused of killing Ethan Schmidt, an assistant professor of history at Delta State University, where both men taught. Schmidt was shot to death in his office on the school's campus in Cleveland, Mississippi, Monday morning.

Police in Gautier, Mississippi, about 300 miles away from the university, also described Lamb as a suspect in a homicide that occurred there Monday morning.

Gautier Police Chief Dante Elben said Lamb was wanted in the shooting death of 41-year-old Amy Prentiss. Lamb and Prentiss lived together, Gautier Police Lt. Scott Wilson told reporters.

At some point Monday, Elben said, Lamb spoke with police and told them "he wasn't going to jail."

When police finally closed in on him late Monday night, he ran from his car into the woods. Officers then heard a single gunshot and found his body.

Police: Motive unknown

Investigators haven't detailed Lamb's relationship with Schmidt or explained why they believe he pulled the trigger.

"Right now we have no motive, and we're not going to speculate on a motive until we have facts in hand," Cleveland Police Chief Charles Bingham told reporters.

Gautier Police also said they hadn't pinpointed a motive in the case.

Both Lamb and Schmidt are listed in an online directory for faculty of social sciences and history. Photos on Delta State's website show them smiling together at a 2013 Christmas party.