Tears stream down 24-year-old Nadine Ascencao's cheeks as she talks about the man she once loved—Boston Marathon bomber Tamerlan Tsarnaev.
"I just can't believe he would do something like that," said Ascencao.
Ascencao and Tamerlan had a hot and heavy romance for three years. But they kept the relationship secret because she is not muslim.
Ascencao told INSIDE EDITION's Deborah Norville, "He was afraid that his family would see us together."
"And that would be a problem?" asked Norville.
'That would be a big problem, yeah," she replied.
Tamerlan was athletic and handsome, and romanced her with flowers and gifts.
"I was really, really in love with him," she said.
But he was also sinister and abusive.
Norville asked, "Was he controlling?"
"Yes. Very controlling. He would control what I would wear. He wouldn't let me wear things that would be too tight on me. He said that that's disgusting men would look at me like that."
"Did he call you names?"
"Yeah, he was just like, 'You look like a slut,'" said Ascencao.
She saw Tamerlan change from a party-loving playboy to a radical Muslim.
"We stopped sleeping together, because he said it was a sin for us to sleep together," she said. "He started praying five times a day. Before, I would barely see him praying."
Norville asked, "Did he ever talk about hating America?"
Ascencao answered, "I remember once he told me: 'You know who runs America? The Jews run America.'"
One night, she says she discovered she had a rival: Katherine Russell, who later converted to Islam and married Tamerlan. Ascencao says she even confronted Russell in a phone call.
"Did you guys sleep together? And she said 'Yes, we did.' And that was it for me," said Ascencao.
The last straw for Ascencao was when Tamerlan physically attacked her in the street because she was wearing shorts.
"He literally grabbed my jaw and was yelling, 'You're not going to wear this! You understand what I'm saying?' And he just slapped me across the face."
She called 911. Tamerlan was charged with aggravated assault and battery, but she never pressed charges.
Today, she's haunted by the thought that if she had, Tamerlan could have been deported and the deadly bombings might never have happened.
Norville asked, "Do you regret that you didn't press those charges?"
"Now I do, of course," she answered.
Four years after their break up, Tamerlan was just an unpleasant memory, then came the marathon bombings.
She didn't recognize Tamerlan in the surveillance images of the bombers, but she did think she recognized his brother Dzhokar.
"I looked at the TV and said, 'Wow! That almost looks like my ex-boyfriend's brother,'" she recalled.
Hours later, her home was raided.
"Know, knock, knock, open up, FBI. That's what you heard?" asked Norville.
"We were awakened by the FBI at my house, yeah, searching for them."
Ascencao says she's disturbed by the knowledge that her first lover is responsible for such an outrageous act.
Norville asked, "As a woman, how do you come to grips with the fact that you gave yourself to this man who proved to be a monster?"
She replied, "I can't think about that. It drives me insane to think about that."