Accused Alabama shooter Amy Bishop screamed and cursed at children, instigating confrontations with their parents, according to former neighbors who painted a frightening portrait of an woman accused of a killing rampage.
Former Massachusetts neighbors described the brilliant scientist as a woman who 15 years ago had "face-to-face, nose-to-nose confrontations" over evening basketball games, skateboarders and even whether an ice cream truck would be allowed on the child-friendly street.
"She picked fights with them," said one neighbor, who did not want to be identified because Bishop's children return summers to visit their grandparents -- Judy and Samuel Bishop -- who still live on Fille Street in quiet Ipswich, Mass.
"I just don't want to alienate them," she told ABCNews.com.
"The ice cream truck was banished from the street because [Bishop] told them her children were lactose intolerant," said the neighbor. "She even had one of the children's teachers fired."
Last week Bishop was arrested for killing three professors and injuring three others -- all colleagues at University of Alabama in Huntsville -- during a faculty meeting. She is currently on suicide watch.
Soon more disturbing news emerged from Bishop's background. Investigators unearthed several disturbing pieces to the puzzle of the suspect, an accomplished cellular biologist and mother of four children aged 8 to 18.
In 1986, she shot her then 18-year-old brother Seth Bishop with a shotgun at their home in Braintree, Mass., but was never charged in the shooting.
And in 1993, she and her husband were questioned by police after a pipe bomb was mailed to one of Bishop's colleagues, Harvard Medical School professor Dr. Paul Rosenberg.
James Anderson has said that he and his wife were cleared in the mail bomb investigation and were never suspects.
Anderson told ABC affiliate WCVB-TV in Boston Monday that he had no idea why his wife would shoot their co-workers.
"Nobody understands what happened. Nobody knew," he said.
Anderson told The Associated Press that he and Bishop went to a shooting range just weeks before the killing, but said the family did not own a gun.
Though many at the university had heard grumblings that she had been denied tenure, police, psychological experts and even her own family say her motivation is an enigma.
"For a faculty member to murder colleagues after denial of tenure would probably require 'standard' experiences of disappointment, a sense of betrayal, and desperation and the additional burden of mental illness, either a severe depression or some form of psychosis," said Dr. Stephen Shuchter, professor of clinical psychiatry emeritus at The University of California, San Diego.
"We are likely to learn about these only if the perpetrator chooses to defend herself by presenting the mitigating circumstances of an insanity defense," he told ABCNews.com.
Meanwhile, Bishop's family and members of the community are struggling to understand what happened.
Sherry Foley, 63, who lives in the same Alabama neighborhood as Bishop, was still in shock over her arrest.
"You can't believe that someone you know that lives just down the street can do something like this," she said. "It's like with sex offenders. You never really know what people are and they might be living right next to you."