By Colleen Jenkins

(Reuters)
- A Mississippi college instructor suspected of gunning down his
live-in girlfriend and a professor colleague before taking his own life,
left behind a note of apology, police said on Tuesday.
But
Shannon Lamb, who taught social science and geography at Delta State
University, gave no motive for the killings that prompted a campus
lockdown and manhunt on Monday before he shot himself as he was cornered
by authorities, investigators said.
Police
said Lamb, 45, shot and killed Amy Prentiss, 41, at the home they
shared in Gautier, Mississippi, before driving 300 miles (480 km) to
Delta State, where he fatally shot Ethan Schmidt, an assistant professor
of American history.
"I am so very sorry," read the
handwritten note Lamb signed and left at his home. "I wish I could take
it back. I loved Amy and she is the only person who ever loved me."
After
arriving on Monday morning at the university campus in Cleveland,
Mississippi, Lamb called police to report he had killed Prentiss the
night before, Gautier police officer Matt Hoggatt told a news
conference.
Lamb
gave no explanation for the shooting and did not indicate plans to harm
anyone else, Hoggatt said. Police said it did not appear the shooting
victims knew each other.
Lamb,
a father and part-time musician, had worked at the university since
2009. He was teaching two online courses during the autumn semester and
did not want a full load, citing medical issues, university President
William LaForge said.
Hoggatt said there was no record of domestic violence between Prentiss and Lamb.
"We don't know why this man did what he did," said Cleveland Police Chief Charles "Buster" Bingham.
The
university canceled events commemorating its 90th anniversary and
instead planned a candlelight vigil on Tuesday to honor Schmidt, 39, a
married father of three children who joined the faculty in 2013. LaForge
praised him as a "star" professor.
The Delta State
shooting followed deadly shootings on U.S. college campuses in recent
weeks, including at Sacramento City College in California, Texas
Southern University and Georgia's Savannah State University.
While
on the run on Monday, Lamb made statements to family members, which
were relayed to police, that he would not turn himself in, Hoggatt said.
After
Lamb's car was spotted traveling across a bridge from Arkansas, and
police in Greenville, Mississippi, began following him, he jumped from
the vehicle and ran into a wooded area, law enforcement said. Officers
then heard a gunshot.
(Reporting by Colleen Jenkins in Winston-Salem, N.C.; Additional
reporting by Victoria Cavaliere; Editing by Andrew Hay and Peter Cooney)