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."
University of Alabama colleague Dick Reeves remembers Bishop as someone dedicated to saving lives, researching cures for diseases like Multiple Sclerosis and Alzheimers. Reaves, the executive director of the Huntsville Angel Network, called Bishop "a very passionate person about everything she did."
Reeves says Bishop became frustrated with how quickly cell samples grown in traditional plastic Petri dishes would die.
"Every time she took the lid off she risked contamination," said Reeves, noting that Petri dishes were invented in 1877 and that samples grown in them rarely live more than 48 hours.
Reeves said Bishop developed a better system for incubating expensive brain and nerve tissue samples, hoping to make them live longer, save researchers money, and allow for more efficient testing and observation of diseased tissue samples. The system was patented by the University of Alabama.
"Right now things are very hectic up here trying to sort out what is going on," said Bishop's father-in-law, Jim E. Anderson Sr., who lives three hours away in Prattsville, Ala.
"In the academic world when you are dealing with PhDs and grants and tenure and all that -- it's in it's own world," he told ABCNews.com. "I suspect somebody in that meeting room was probably an antagonist and I would like to know who that was."
Bishop and her husband, an Alabama native who was raised in New England, met when they were undergraduates at Northeastern University.
They settled in the suburban seaside town of Ipswich, while Bishop worked at Harvard's Children's Hospital in the 1990s.
Sylvia Fluckiger, a lab technician who worked with Bishop then, described her as "an oddball" and "socially a little awkward," according to the Boston Globe. But Dick Reeves, who worked with Bishop in developing her cell incubator research, said there was no clue she might one day be violent.
Many of her current students have praised her.
"Dr. Bishop is brilliant," said one who gave Bishop high marks on RateMyTeacher.com. "Her research is fascinating. She will surely get the Nobel Prize. She is the best teacher I have ever had."
But among former neighbors, Bishop was cantankerous and not well liked.
Ipswich police logged two calls for neighborhood disputes from Bishop, and in 2002, she reported receiving harassing calls, according to local reports.
Once, neighbors organized a block party and didn't tell Bishop because of conflicts she had with people.
"We never had any issue with them directly," said the grandmother who knew the family. "But it was very uncomfortable with the other neighbors. Amy was not friendly. The high school kids at the time were very in to sports and they'd come out and play from 8:30 to 10 at night. The noise was bothersome to her."
Their father worked from home and did most of the child rearing, according to the source. Bishop, she said, had mentioned an interest in homeschooling the children.
"He was quite pleasant," she said. "But I think she was the leading force in the family."
The children, then aged 1 to about 6, were "kind of meek," but well-behaved, she said. But Bishop's social skills were "suspect."
Her family denies there were any signs of mental illness, but her father-in-law said Bishop was "different."
Anderson Sr. said that in the past Bishop had "voiced concerns" over her safety on campus.
"Huntsville is not a very friendly community in certain specific areas," he said. "I have a gut feeling that she may have had a weapon for stalkers."
"I don't know if she would have shared that with [her husband] or not," said Anderson Sr. "It was an off the cuff remark to me about someone in her campus neighborhood she had to keep an out eye out for."
Anderson Sr., 71, said that his immediate worry was for the "safety of the family," not knowing who might be "revengeful."
When asked if she had personal issues, he said, "I think that's probably true," especially after she faced a prospect of unemployment after being rejected for tenure.
Whether that event alone could have triggered an act of violence is unlikely, say mental health experts.
But many psychiatric disorders can go undiagnosed for years, especially for those who lead insular lives.
"People in science and computers are solitary people," said Dr. Igor Galynker, associate chairman for the department of psychiatry and behavioral science at psychiatry at Beth Israel Medical Center in New York City and professor of psychiatry at Albert Einstein college of Medicine. .
"They work in solitude and they don't need to interact in complex social situations and can be paranoid for a long time without someone realizing."
Schizophrenia can be marked by social isolation, odd behavior, "strange disordered" thinking and speaking, poor hygiene and lack of friends, according to Galynker.
Often people don't notice signs until more serious symptoms emerge.
"Brilliant scientists are supposed to be crazy," he told ABCNews.com.
John Nash, the Nobel-winning economist from Princeton, portrayed in "A Beautiful Mind," could be coherent in his field, even as he suffered from schizophrenia.
Anti-social personality disorders can also result behavior that is "incompatible with laws," like stealing or shooting, he said. And in narcissism, a person can display disregard for the feelings of others or seek self-aggrandizement and, like Bernie Madoff, can be "very charming."
Psychotics like Seung-Hui Cho, the student who who killed 31 at Virginia Tech in 2007, are particularly dangerous.
Killers like Cho view others as inconsequential and often humiliation can set off a psychotic depression that could make a person violent or suicidal, said Galynker.
"Look at a 3-year-old before their conscience is developed," he told ABCNews.com. "You want to escape bad consequences, and you don't have the internal mechanism to want to be good. If you do become angered or enraged, nothing inside of you is telling you that it's bad."
"There is the fear of getting caught, and then you get away with it and you harbor a sense that all these other people are crazy," said Ochberg. "There's a sense of entitlement."
Any of those psychiatric disorders could justify an insanity defense -- lacking the capacity to know right from wrong , according to both psychiatrists.
"In general being a woman and a mother makes you more in tune with your feelings, more nurturing and sympathetic," said Ochberg. "I believe men are from Mars and women are from Venus, but some women are from Mars."