Sept. 20, 2011 -- Nearly 20 years of daily insults, threats, and physical abuse that allegedly left her with countless bruises and a broken nose ended for Barbara Sheehan in 2008 when she shot her police officer husband 11 times.
She told police it was self defense.
Sheehan, a mother of two and a school secretary from Queens, N.Y., is on trial for murder. Experts say the trial could be a critical test for the so-called battered-woman defense in which attorneys argue a history of abuse ultimately leads their defendants to kill.
On Monday Sheehan took the stand and said her decision to shoot her husband, retired cop Raymond Sheehan, as he shaved in his bathroom on the morning of Feb. 18, 2008 was about self defense and not cold-blooded revenge.
"I knew he was positively going to kill me," Sheehan testified. "He would always chase me and catch me. So I knew he would catch me. So I shot the gun. I don't know how many times I shot. I just fired. I stopped firing when I didn't feel threatened anymore. I grabbed the guns, closed the door and ran downstairs."
Barbara Sheehan Using Battered Woman Defense in Death of Husband
In a 2008 interview with ABC News, Sheehan, who at the time had been released on $1 million bail, described an allegedly horrific beating she sustained while on vacation in 2007 with her husband.
"The walls in the hotel were like cinder block and he kept banging my face into it until my head cracked open. There was blood all over the room, and I wound up in the hospital on the island of Jamaica," she told ABC News.
But it was on the eve of another vacation that led to Raymond Sheehan's death, Barbara testified Monday. That morning the couple fought over whether Barbara would accompany Raymond to Florida. Fearing a similar incident like the one in Jamaica, Sheehan said she refused, but Raymond put a gun to her head.
Sheehan fled to a friend's house, but later returned to the home to find an angry Raymond in the bathroom. Fearing the worst she picked up one of the two guns her husband kept at home, she said, "thinking maybe he wouldn't shoot me if I had the gun."
Raymond, who she testified kept a gun on him at all times, even in the bathroom, emerged with his pistol and "he said he was going to kill me."
"So I shot the gun I had in my hand. He had the big gun, I had the little gun. I don't know how many times I shot it. I couldn't aim it. I just shot. I never shot a gun before," she said.
Wounded but still alive, she said, Raymond slumped to the ground and reached for his gun. She grabbed it from him, she testified, and emptied it into her husband.
"I didn't intend to kill him," she said. "I just wanted him to stop and not kill me."
Sheehan said she could never go to the police because Raymond was a former NYPD officer and told her no one would ever help her.
Prosecutors say Raymond Sheehan was a devoted father, husband and police officer. In cross-examination Monday, they called all accusations of abuse "alleged" and repeatedly mentioned that Sheehan had "shot and killed" her husband.
Sheehan's 25-year-old daughter is to testify today in her mother's defense.
Legal experts say the battered-women's defense is a tough case to make for attorneys.
"Its' not easy. A battered-woman defense is always an uphill climb," said defense attorney Gloria Allred. "There are a lot of questions her lawyers are going to need to answer for the jury. Why didn't she report the abuse? Did she tell anyone?"
Prosecutors, she said, will defuse her argument by asking those questions. She has to prove that a reasonable battered wife of a cop would have felt threatened enough to commit the crime and that she had no other options at the time.
In 2010, a New York woman accused of murdering her husband successfully used the battered woman defense and was acquitted. Shanique Simmons had been routinely abused by her husband and was even raped, she testified. Simmons stabbed her unarmed husband in the hallway of their Bronx apartment, but claimed self defense.
Calls by ABCNews.com to prosecutors and Sheehan's attorney were not immediately returned.