Behind Closed Doors: The abusive relationship ?

In a tree-lined neighborhood in upstate New York, Susan, 47, a mother of three, never imagined her life would spin out of control.

But she found herself in a marriage that escalated from controlling to violent -- as she says she became a victim of domestic violence.

According to the Centers for Disease Control and Prevention, approximately 5.3 million incidents of intimate partner violence occur each year in the United States.

But Susan's case is unique because her abuse was documented in a disturbing 51-minute home videotape.

Four years ago, Susan's husband ordered their 13-year-old son to videotape his mother being verbally and physically assaulted.

The chilling tape took a look behind closed doors into the brutal reality of domestic violence.

Susan told her story for the first time to ABC News' Diane Sawyer.

Beginning of the Abuse

Susan was just 18 when she first met and fell in love with Ulner, a 26-year-old man she saw on stage.

Ulner was a bass guitarist in a popular local band, while Susan had just finished her first year of college.

They started dating immediately. Eventually, they got married and started a family, with Susan working at a health-insurance company.

At first, Ulner was just controlling, not so different from her own father. But, the more she complied, the more he demanded.

"The controlling was absolutely there from the beginning. … Without me recognizing it," Susan said.

The physical abuse started more than 10 years into the marriage, when, according to Susan, she forgot an item at a nearby grocery store.

"He hurt me," Susan said. "He hurt me badly. I just couldn't believe it. It's like you're almost outside your body watching and saying, 'This can't be happening.'"

Susan said that Ulner cut her off from her father and her family for many years, leaving her isolated with no one to talk to, and completely under his control.

Susan Goes Back to Work

In 2002, the family started struggling financially, and Susan returned to work at a new job.

The only escape she had from her controlling and abusive home life was her new friend and boss, Lynne Jasper.

Jasper and Susan were friends and working mothers who bonded by sharing stories about their kids.

"I would have thought it was a rock-solid marriage," Jasper said.

Shortly thereafter, Jasper overheard several phone calls between Susan and Ulner, and said she was horrified to hear Susan refer to him as "master."

"'Yes, master. No, master.' You hear it the first couple of times, you think, 'Wow, what a sick individual,'" Jasper said. "After you got to hear the conversations and know her [Susan], [you learned] that her dedication wasn't out of love and friendship, it was more out of fear and control."

Jasper knew something was wrong and started collecting clues -- even taking notes in her datebook, recording behavioral changes and visible physical injuries, marks and bruises on Susan.

On May 6, 2003, she wrote, "Talk to Susan re: head" because of a visible wound on Susan's head.

Jasper asked Susan about her mark, and Susan said she had gotten the lump from a box she was pulling down in a closet, saying that it had hit her in the eye.

Jasper let it go for the moment, but still had her concerns.

The physical violence intensified between Susan and Ulner.

"As markings on the calendar got closer and closer together and more frequent, then it just became clearer that I wasn't necessarily making a mountain out of a molehill," Jasper said.

Susan Confronted

On May 23, 2003, Jasper noted "Bruise/Susan" in her datebook.

Susan arrived to work an hour late with makeup piled on, attempting to cover her bruises.

Jasper immediately noticed a large bruise on Susan's face from a beating.

Jasper decided to finally confront Susan, saying, "'I think there's something you want to tell me, and I need you to know that it's OK to do that.' And she did. She just started to cry, and we had gone into a room privately, and I closed the blinds. She told me a lot of what was going on. But you know what? [It was] not even close to the whole story, not even close to how bad it was."

Later, Jasper found a letter in her desk drawer from Susan -- a final warning and a farewell in case anything happened.

"If anything should happen to me or if I should turn up missing, it is possible my husband was involved," the letter said. "I love you so much, my children. Please forgive me for the things you have seen in your young life. … Know you were loved by your mother."

Jasper was so upset by this letter -- a mother bidding farewell to her children -- that she alerted local police.

Susan was falling apart, saying, "He had literally, physically and mentally beat me down to nothing. I thought I was not as good as a piece of dirt on his shoe."

The Breaking Point

A month later, Susan hit her breaking point.

It was the day Ulner instructed their 13-year-old son to videotape the verbal and physical assault upon her.

The horrifying tape lasts 51 minutes as the rants get louder and more violent.

"You don't even look at me with that stupid look on your face. Don't you get tired of that [expletive]," Ulner yells.

"Zoom in on that heifer," Ulner directs his son. "Zoom in. Do you see a tear?"

He continues to yell, "You don't know what to do. Look at your stupid [expletive]. Look at the way you look!"

Ulner makes his son videotape what he considers to be his justifiable anger at his wife, and at the end of the tape -- after what seems like endless verbal abuse -- Ulner slaps, beats and strangles his wife with their younger children as witnesses.

Later that night, Ulner played the tape for his family as an instructional video to teach his wife and children a lesson about the flaws of their mother.

"The whole family had to sit and watch that night," said Lisa Bloch Rodwin, an assistant district attorney for Erie County, N.Y. "And then dad would stop it, pause it, and say, 'Do you see what she did wrong? Do you see how she made me do this to her?'"

Susan now knew she had to get her children and herself away from Ulner.

The next day, Susan planned her escape at work.

The Escape

"When Susan walked in the next day, she was beaten and marked worse than I have ever seen," Jasper said. "I remember saying to her, 'It's gotta stop. Today's the day.'"

Susan replied, "Today's the day."

With the help of the Amherst, N.Y., police, Susan and her two sons escaped and entered a shelter.

Susan's oldest daughter chose to return home to her father.

Susan headed to court to face Ulner.

Rodwin, who also was chief of the Prosecutor's Office's Domestic Violence Bureau, gathered the evidence.

The video proved a single incident of violence, and Jasper's calendar became an important piece of physical evidence for the prosecution's case.

Armed with Susan and her sons' testimony, the calendar, the videotape and Jasper's testimony, the prosecution charged Ulner with 12 separate assaults against his wife.

Ulner was found guilty on all counts, and the judge handed down a sentence of 36 years, which, to Rodwin's knowledge, is the longest in New York history for a domestic-violence case in which the victim wasn't killed.

Today, four years later, Susan is moving on with her life, living with her two sons. "We continue to grow. We're in a much better place," Susan said. Her boys are doing well, despite the painful memories.

"My children will absolutely have to deal and remember and hear in the back of their minds what happened in our home," she said. "Those visual pictures will never go away for them."

They all remain in therapy, including the daughter who is also in counseling with her mother. "We're making great strides," Susan said. "She's doing well." And in what Susan describes as a "huge step," she and her three children have all gotten together on several occasions. "We're pulling our family together."

Susan and Jasper, her former boss, remain close friends.

Susan continues to spread domestic-violence awareness and uses her abuse video at police academies as a tool to put a personal face on this epidemic. She also hopes to start a foundation to help children of domestic violence. Recently, a family violence center named its Courage to Change award after Susan. It will be awarded annually to a victim or advocate of domestic violence.

Story Source: http://abcnews.go.com/2020