HUNTSVILLE, Ala. — A Harvard-educated biologist was sentenced to life in prison without parole Monday after being convicted of going on a shooting rampage during a faculty meeting at an Alabama university, killing three colleagues and wounding three others in 2010.
The jury deliberated for only 20 minutes before convicting Amy Bishop. The former professor at the University of Alabama in Hunstville showed no reaction as the verdict was read. She did not speak in court, but her lawyer said she has often expressed great remorse to the victims and their families.
‘‘She is shattered beyond belief,’’ lawyer Roy Miller said.
Bishop avoided a death sentence by pleading guilty earlier this month to the shootings on Feb. 12, 2010. Before the guilty plea — which she signed with a barely legible scrawl — her lawyers had said they planned to use an insanity defense.
However, she was required to have a brief trial because she admitted to a capital murder charge.
Bishop could also still face a trial in Massachusetts, where she is charged in the 1986 killing of her 18-year-old brother. Seth Bishop’s death had been ruled an accident after Amy Bishop told investigators she shot him in the family’s Braintree home as she tried to unload her father’s gun.
But the Alabama shootings prompted a new investigation and charges. Norfolk District Attorney Michael W. Morrissey plans to make an announcement by the end of the week regarding those charges, said David Traub, a spokesman for his office, on Monday.
In Alabama, Bishop killed her boss, Biology Department chairman Gopi Padila, and professors Maria Ragland Davis and Adriel Johnson. Professor Joseph Leahy, staff aide Stephanie Monticciolo, and assistant professor Luis Cruz-Vera were shot and wounded.
A police investigator testified Monday during the brief trial that Bishop denied having anything to do with the rampage. During testimony Monday, Bishop shook her head any time the judge or prosecutors described the killings as intentional.
Investigator Charlie Gray also said police believe Bishop opened fire during the faculty meeting because she was angry over being denied tenure, which effectively ended her career at the University of Alabama in Huntsville.
‘‘She would say, ‘It didn’t happen. I wasn’t there. It wasn’t me,’ ’’ Gray said.
Sitting behind prosecutors were relatives of the people killed in the February 2010 rampage. At least one of the shooting victims who survived also was present, though none spoke to reporters.
The only other witness to testify Monday was Debra Moriarity, now the chairwoman of biological sciences at the Alabama university. She testified about how a routine Friday afternoon faculty meeting turned into a scene of carnage with no warning.
Moriarity testified that Amy Bishop sat unusually silent during the nearly hourlong faculty meeting. ‘‘And there was a loud bang,’’ she said.
Moriarity said more shots followed in quick succession without Bishop ever saying a word. Moriarity said she was looking directly at Bishop when she shot professor Maria Ragland Davis, who was killed instantly while seated at the table.
‘‘I was saying, ‘Stop Amy, stop. Don’t do this. I’ve helped you before, I’ll help you again.’’’
Moriarity said Bishop pointed the gun at her and pulled the trigger, but nothing happened. She said Bishop continued trying to shoot her in a hall outside, but the gun had jammed.
Globe correspondent Melanie Dostis contributed to this report.