It's been one week since two teen sisters were found shot to death inside a cab outside a Texas hotel, and their father, who police say is the sole suspect in the New Year's Day killings, remains at large.
Authorities tell ABC News that the investigation so far has produced few solid leads as to Yaser Abdel Said's whereabouts, and they fear he may have fled the country, perhaps even to his native Egypt. Police say they believe Said, a taxi driver, was driving the cab that evening.
"As far as I know, there haven't been any sightings of him," Officer David Tull, spokesman for the Irving Police Department, told ABC News about the 50-year-old Said. "He's had a week now, so he could be pretty much anywhere."
The sisters, Sarah Yaser Said, 17, and Amina Yaser Said, 18, were buried Saturday. Their mother, Patricia Said, broke her silence about the case at a candlelight vigil for her daughters Thursday. She reportedly told a crowd of mourners that the girls — especially their vibrant smiles — would be missed.
Before the funeral Saturday, Patricia Said made a public appeal for her husband to turn himself in. "We will not quit until we find you," she said. "If it's the last thing I do, I promise, I will find you."
The couple's son, 19-year-old Islam Said, also spoke to the media, saying that his father had "messed everything up" by murdering his sisters, who have been described as popular students at Lewisville High School and inseparable siblings.
At the vigil Thursday, Islam Said also tried to squash rumors that the family's Muslim heritage may have had something to do with his sisters' murders.
"Religion has nothing to do with this and it was very wrong," Islam Said said, according to the Star-Telegram in Texas. "Islam is not a bad religion."
Still, the case has generated significant speculation — including by some friends of the girls — that the father's motive may have been some sort of an "honor killing" in the Muslim tradition. Specifically, the reported Westernized behavior of the teens, including the boys they dated, may have brought shame to a father said to be strict and religious, prompting the killings.
While acknowledging that the idea of an "honor killing" is being talked about widely in the Texas community, Tull said the Irving Police Department would not comment on the speculation and still have not confirmed a motive beyond some type of existing domestic discord.
"There's a lot of facets to this case," Tull said when asked about the "honor killing" motive. "We're very well aware of the various domestic issues and the dynamics of this family."
On a Facebook page devoted to the teens' memories, many friends and strangers have offered prayers and memories of two classmates described as full of life and typical of American high school students, some even offered theories on the murders.
Group member Morgan Brooke Lee wrote that she was formerly a classmate with Sarah Yaser Said, but that the Saids abruptly moved to Lewisville. "I found out later from Sarah on MySpace it was because [Yaser Abdel Said] had found out about a boy Amina was dating," Lee wrote in a post.