The professor accused of killing three colleagues at the University of Alabama Friday had previous run-in's with police.
The revelation has prompted relatives of the slain professors to wonder why suspected shooter Amy Bishop was hired at the school to begin with.
Investigators say Bishop opened fired during a faculty meeting on campus. She was reportedly upset over being denied tenure.
Twenty-four years ago Bishop shot and killed her 18-year-old brother at their home in Braintree, Mass.
However, Bishop said it was an accidental discharge and was never prosecuted. That case is now being re-opened.
Bishop was also a suspect in the 1993 attempted mail bombing of a Harvard Medical School professor.
In an interview with ABC's Good Morning America the widower and two stepdaughters of one of the slain professors expressed shock that Bishop was hired in light of her checkered past.
"I think they need to do a little more investigation when coming down to hiring teachers and things like that. Maybe looking a little deeper into their past about certain things. This is a lot coming out ... It's a shocker," said Melissa Davis, whose stepmother was shooting victim Maria Ragland Davis.
Police arrested Bishop, the mother of four, soon after Friday's incident. According to jail records, three counts of attempted murder were filed against her over the weekend.