By Verna Gates

HUNTSVILLE, Alabama (Reuters) - A former Alabama biology professor who pleaded guilty to killing three colleagues and wounding three others in a 2010 shooting rampage was sentenced to life in prison without parole on Monday after a jury convicted her in a shortened trial.

Amy Bishop, 47, avoided a death sentence by admitting earlier this month to gunning down her colleagues during a biology department staff meeting at the University of Alabama at Huntsville.

Alabama law requires a jury to decide the punishment and confirm a guilty plea for a capital murder charge.

Bishop's defense attorneys did not contest the facts of the case during the abbreviated proceedings on Monday.

"She has admitted she did these terrible things," defense attorney Robert Tuten said in his opening statement.

Bishop, a Harvard-trained biologist and mother of four, was accused of shooting her colleagues execution-style in February 2010. Colleagues believed Bishop was angry that the school had denied her tenure.

The trial on Monday took less than two hours and featured only two witnesses. One was Bishop's former colleague Debra Moriarity, who recalled how she tried to take Bishop down after the woman started firing during the meeting.

TRYING TO STOP SHOOTING

Trained in gun safety by her hunter father, Moriarity testified that she ducked and crawled under a table to grab Bishop's legs.

"I was yelling, ‘Stop, Amy! Stop! Don't do this!'" said Moriarity, who is now chairwoman of the biology department.

Moriarity said Bishop then pointed the gun at her. As Moriarity begged for her life, Bishop repeatedly pulled the trigger but the gun jammed, Moriarity testified. She said Bishop was silent during the attack.

As a police investigator showed jurors photos of the dead professors on Monday, Bishop put her head on the defense table and softly sobbed. Bishop, who last year had pleaded not guilty by reason of mental disease or defect, did not speak during the trial.

After her arrest in Alabama, authorities in Braintree, Massachusetts, charged Bishop with the 1986 shooting death of her teenage brother.

Authorities in Massachusetts were awaiting the outcome of the Alabama trial before deciding how to proceed in their case.

Jurors on Monday did not have to weigh Bishop's guilt in the attempted murder charges, for which Circuit Judge Alan Mann sentenced her to three consecutive life sentences.

After the trial, professor Joseph Leahy, who lost an eye in the shooting and has just returned to teaching, said he felt the verdict was just.

"Seeing the photos was tough - I was seeing the bodies of my friends," he said. "They took the first three shots, and I got the fourth. I feel fortunate to be alive."

(Reporting by Verna Gates; Writing by Colleen Jenkins; Editing by Cynthia Osterman)