DALLAS — A man on the run from police since his teenage daughters were found shot to death in a taxicab on New Year's Day had threatened to hurt one of the girls for dating a non-Muslim boy, according to police documents.

Authorities deflected questions Wednesday about whether the sisters, who had both a Christian and Muslim memorial service, might have been victims of an "honor killing."

"There's a lot of speculation out there right now," Irving police spokesman Richard Gilmette said. "We have no solid information."

Amina Said, 18, and her sister Sarah, 17, were found shot multiple times in a cab outside a suburban Dallas hotel. Police found them after one of the girls called 911 from a cell phone and said she was dying. A capital murder warrant has been issued for Yaser Said, 50, who has not been seen since the Lewisville High School students were found dead.

Gail Gattrell, the sisters' great-aunt, has called the deaths an "honor killing," in which a woman is murdered by a relative to protect her family's honor.

According to a police report released Tuesday, a family member told investigators that Yaser Said threatened "bodily harm" against Sarah for going on a date with a non-Muslim.

The police documents, first obtained by Dallas television station KXAS, also show that Patricia Said fled with her daughters in the week before the girls were killed because she was in "great fear for her life."

She asked police if she needed to do anything to prevent her husband from getting information about the girls when they enrolled in a different school, according to the documents.

Gilmette said police had no information on the father's whereabouts. The department on Wednesday taped a segment for "America's Most Wanted" in hopes of finding him, Gilmette said.