ANGRY DAD: Mr Said had allegedly threatened to harm the daughters for dating non-Muslims. -- PHOTO: AP

View more photos

Amina, 18, and Sarah, 17, both from the Dallas suburb of Lewisville, were shot dead. Their bodies were found at a hotel carpark in nearby Irving in a taxi that their father Yaser Abdel Said drives.

The police said one of the teens had called 911 just before their murder and said 'over and over again' that she was dying.

Mr Said, 51, had threatened to harm the girls after he learnt they had non-Muslim boyfriends, said their mother Patricia Said, who is a Christian. She said she had feared for her own life.

On Christmas Day, after Mr Said went to work, Mrs Said left with the girls after telling her son Islam that they were going to a convenience store. She had feared that Mr Said, a Muslim immigrant from Egypt with a history of domestic abuse, would harm their daughters.

The three went to stay with the girls' great-aunt Gail Gartell, but returned home on Dec 27 because Mrs Said felt 'guilty'.

Things took a turn for the worse on New Year's Day, when the sisters went with their father to a local restaurant for a talk. According to Irving police, they received a call for help from the teens but were unable to locate them.

It was when someone reported the bodies at the hotel carpark that police were able to put things together.

Mr Said, the prime suspect in the case, had been accused of sexual assault when the teens were nine and eight years old. The accusation was later recanted, police said.

Friends of the teens recalled seeing physical injuries on them that were apparently caused by their father, but said the sisters never reported him as they feared he would be sent to jail.

The clash between Mr Said's culture and the girls' Westernised lifestyle prompted an argument after their funeral, as Christian relatives confronted Muslim relations over the murders.

Ms Gartell had called the murders 'honour killings', in which a male kills a female relative for bringing dishonour to the family, she told The Dallas Morning News.

However, the allegation was denied by the teens' brother Islam, 19. 'Why is it every time an Arab father kills a daughter, it is an honour killing?' he said in a recent interview.

Mr Said's boss, Mr Massoud Nasseri, added: 'This is not an honour killing. This was just a good man who went crazy.'

But Irving mosque imam Zia Sheikh has denounced the act, saying that such killings have no place in Islam, Dallasnews.com reported.