When Jennifer Joyce Sheehan's mother killed her father, she was relieved.
"He was such a monster in all of our lives," Sheehan told ABCNews.com. "I was always so afraid that he was going to kill my mom. It's such a relief that he's gone."
Barbara Sheehan killed her husband, retired New York police officer Raymond Sheehan, as he shaved in the bathroom on the morning of Feb. 18, 2008. She shot him 11 times after suffering years of violent abuse and threats from him.
"My mom would never hurt anybody," Jennifer Sheehan said. "He [Raymond Sheehan] would say it all the time—that he was going to kill her, us, the rest of the family. If she didn't protect herself, he would have not only killed her, but the rest of us, too."
But after the relief wore off, Jennifer Sheehan, 26, and her brother Raymond Sheehan, 22, faced another terrifying reality—the possibility that they could lose their mother to life in prison for murder.
The siblings tell their mother's story in their new book, "In Bed with the Badge: The Barbara Sheehan Story," available today.
"We were stunned," Raymond Sheehan writes in the book. "It all happened so fast that for a moment I lost my equilibrium. I felt as though I had been spun around a hundred times, then forced to stand still and walk."
When the case went to trial in 2011, Jennifer and Raymond Sheehan stood by their mother and testified against their father.
The siblings are part of a long line of children who have watched their parents go through high-profile trials.
Just this year, the children of ex-Penn State football coach Jerry Sandusky, two-time presidential candidate John Edwards and legendary pitcher Roger Clemens have been subjected to the grueling and invasive ordeal of watching their fathers go through trials.
But what effect does the trial process have on these offspring, both young and older, especially in highly publicized and scrutinized cases?
"You have the parents undergoing a huge stressor and the child trying to cope with how that affects them and their world," Dr. Alan Kazdin, a professor at the Yale University department of psychology, told ABCNews.com. "The fallout could be huge."
The stress is the first thing Jennifer Sheehan recalls from her mother's trial.
"Just being there for the short amount of time that I was, listening to closing arguments and a couple of people testifying, waiting for the jury's decision—the anxiety is just through the roof," she said. "There's no way to describe it. You don't even really have feelings. You're so anxious, you're so scared."
Barbara Sheehan was charged with second-degree murder and two gun possession charges. She faced 25 years to life in prison, but was acquitted of murder and one of the gun charges. She could still face jail time for the second gun charge. Jennifer Sheehan was 25 years old during the trial in Queens, N.Y. and Raymond Sheehan was 22.
Jennifer Sheehan said that one of the most painful parts of the trial was being shocked by the lies she felt her father's side of the family told in court.
She said that in the time leading up to her father's death, her mother had told his family that things were really bad and that she needed their help. Jennifer Sheehan said her father's family shut them out and testified in court that nothing was wrong with their son.