DA won't pursue case against prof in brother's death

Huntsville Times/AP Amy Bishop is escorted by sheriff's deputies at the Madison County Courthouse in Hunstville, Ala., on Sept. 11. By NBC News staff and wire services Amy Bishop, the biology professor sentenced to life in prison earlier this week for killing three colleagues, will not be prosecuted for murdering her brother in 1986, the Massachusetts district attorney looking at that case said Friday, according to the Boston Globe. Bishop's fatal shooting of her younger brother Seth at the family's home in Braintree, Mass. was dismissed as an accident at the time. But the February 2010 shooting spree that left three of her colleagues dead and three others wounded at the University of Alabama at Huntsville sparked an inquest into Seth Bishop's death, which was then reopened as a homicide case. Norfolk District Attorney Michael Morrissey said in a statement Friday that his office would not pursue the first-degree murder charge against Bishop because she is now scheduled to end her life behind bars. "We will not move to have her returned to Massachusetts," Morrissey said, according to the Globe report. "The penalty we would seek for a first-degree murder conviction is already in place." The Harvard-educated biologist opened fire at a faculty meeting in February 2010. Bishop killed her boss, biology department chairman Gopi Padila, plus professors Maria Ragland Davis and Adriel Johnson. Professor Joseph Leahy, staff aide Stephanie Monticciolo and assistant professor Luis Cruz-Vera were wounded. Colleagues believed Bishop was angry that the school had denied her tenure. On Sept. 11, Bishop pleaded guilty to first-degree murder charges. By doing so, she avoided a possible death sentence but was sentenced to life in prison without the possibility of parole. Morrissey said that after talking to his counterpart in Alabama, Madison County District Attorney Robert Broussard, he felt confident that Bishop would never be released from custody, the Globe reported. His office was planning to file what is known as a "nolle prosequi" next week, which would allow prosecutors to revive the first-degree murder charge against her "if circumstances change," it said. Follow Kari Huus on Facebook More content from NBCNews.com: Wolf pack that killed cattle taken out by sharpshooters World War II bombs in Gulf of Mexico need to be checked, experts warn Video: Cheerleaders raise special-needs girls' spirits Lawsuit: Pentagon denied rape victims their constitutional rights US immigration chief: Same-sex ties are family ties A country song about PTSD: 'All you've got left are these pieces' Follow US News from NBCNews.com on Twitter and Facebook