Amy Bishop, the biologist who murdered three colleagues in cold blood and grievously wounded two others, will spend the rest of her life behind bars after an Alabama court sentenced her last week. The Harvard-trained assistant professor had been denied tenure at the University of Alabama in Huntsville. In February 2010, months after her appeal against the decision failed, Bishop, a mother of four, pulled out a 9-millimetre pistol during a faculty meeting in a tiny conference room.

Without saying a word, Bishop methodically shot down fellow biologists Maria Ragland Davis, Adriel Johnson and department chairman Gopi Podilla. A bullet to the head of colleague Joseph Leahy left him, after many months of recovery, blind in his right eye and partially sighted in his left. Staff assistant Stephanie Monticciolo, the department’s mother hen, had the teeth on one side of her mouth knocked out. She sustained shattered sinuses and a broken jaw, and was blinded in one eye.

“Many, many things are better than I could have ever hoped,” Monticciolo’s adult daughter Michele posted on a blog 18 months later. “Some things, however, will never be the same.”

The same is true in the biology department at Huntsville, two and a half years after the shooting. Yet signs of a determined recovery abound. Ten new graduate students enrolled in August. The department has made university biochemist Debra Moriarity its chairwoman, and has hired two new faculty members. Leahy, a microbiologist, is back teaching full-time as of this term. And last week, structural biologists on the faculty hosted an international conference on the crystallization of biological macromolecules, attended by more than 200 scientists.

In the state of Alabama, there are only two possible sentences for capital murder, with which Bishop, now 47, was charged: life in prison with no possibility of parole, or death by lethal injection or electrocution. Prosecutors said almost from the outset that they would seek the death penalty.

At first, Bishop pleaded not guilty “by reason of mental disease or defect”. Then, weeks before the trial was set to open last month, a heartening tale of human generosity began to unfold. It emerged that the spouse of one of the murdered biologists had written to judge Alan Mann, who would have the final say over the sentence if Bishop was found guilty. The letter-writer noted that his or her family had suffered greatly, but added that they could see no benefit in the loss of another life. The writer asked Mann to spare Bishop the death penalty.

The letter prompted Bishop to offer, through her lawyers, to change her plea to guilty if the prosecutors would drop their pursuit of the death penalty. The prosecutors sounded out the other survivors: the nine who had been in the conference room at the time of the shooting, and the families of the dead. None wanted the death penalty. A deal was reached and Bishop changed her plea to guilty.

Robert Broussard, the lead prosecutor on the case, told Nature this week that the common sentiment among the survivors “absolutely” swayed him not to seek the ultimate punishment. And so, on 24 September, after a brief trial, Bishop was sentenced to life behind bars.

In 25 years of prosecuting murders, Broussard said, he has never seen such equanimity in so many people affected by a violent crime. Those who will spend a lifetime bearing the wounds that Amy Bishop inflicted, inside and out, reached deep and found mercy.