Nadine Ascencao, the former girlfriend of Boston Marathon bomber Tamerlan Tsarnaev, revealed he slapped her and beat her head against a car because she was wearing shorts.
Nadine Ascencao, 25, of Cambridge, Massachusetts, said she and Tamerlan Tsarnaev split up after he became so abusive she called police.
The couple dated for three years and she said he became increasingly religious during that time.
Tamerlan Tsarnaev, 26, and his brother Dzhokhar, 19, set off the bomb at the marathon on April 15 that killed three by-standers and injured more than 260 people.
The Boston suspect was killed in a stand-off with police four days later and his young brother is in police custody after being injured in the same shoot-out.
Nadine Ascencao told Inside Edition that Tamerlan Tsarnaev, a former amateur boxer, attacked her after she wore a tank top and shorts to a pool party.
She said he screamed at her “what are you wearing” and then became violent.
Nadine Ascencao said: “He literally grabbed my jaw and he was telling me <<you are not going to wear this, do you understand what I’m saying>> and he kept pushing my head until I hit the car and it hurt and that made me really upset and he just slapped me across the face. But that right there just made me so furious.”
She said she told she was going to dial 911 and he told her to “go ahead”.
Nadine Ascencao said in the interview with Inside Edition: “The police officer goes up to him and she said, <<did you hit her?>>
“He goes, <<I just gave her a little slap>>. She goes <<excuse me what did you just do to her?>>
“[He said] I just gave her a little slap.
“She said, <<turn around sir>> and just handcuffed him.”
Tamerlan Tsarnaev was arrested on domestic assault and battery charges and the mugshots later emerged after he was identified as the suspect in the bomb attack.
However, despite the violent outburst Nadine Ascencao did not press charges, which she says she now regrets.
Nadine Ascencao said: “At that time I was young and really didn’t think it through.”
In previous interviews, Nadine Ascencao said then boyfriend Tamerlan Tsarnaev, who she met at high school, became increasingly religious and was angered if she wore Western clothes.
Tamerlan Tsarnaev later went on to marry Katherine Russell, who converted to Islam.