Sarah Said, 17, and her sister Amina, 18, were killed on New Year's Day, but for nine months authorities deflected questions about whether their father — the prime suspect and the subject of a nationwide manhunt — may have targeted them because of a perceived slight upon his honor.

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The girls' great-aunt, Gail Gartrell, says the girls' Egyptian-born father killed them both because he felt they disgraced the family by dating non-Muslims and acting too Western, and she called the girls' murders an honor killing from the start.

But the FBI held off on calling it an honor killing until just recently, when it made Yaser Abdel Said the "featured fugitive" on its Web site.

"That's what I've been trying to tell everybody all along," Gartrell told FOXNews.com. "I would say that's a victory."

But some Muslims say that calling the case an honor killing goes too far.

"As far as we're concerned, until the motive is proven in a court of law, this is [just] a homicide," Mustafaa Carroll, the executive director of the Council of American-Islamic Relations in Dallas, told FOXNews.com.

He said he worries that terms like "honor killing" may stigmatize the Islamic community. “We (Muslims) don’t have the market on jealous husbands ... or domestic violence,” Carroll said.

The United Nations estimates that 5,000 women are killed worldwide every year in honor killings — mostly in the Middle East, where many countries still have laws that protect men who murder female relatives they believe have engaged in inappropriate activity. A U.N. report includes chilling examples of such cases.

“On the order of clerics, an 18-year-old woman was flogged to death in Batsail, Bangladesh, for "immoral behavior,” the report reads. “In Egypt, a father paraded his daughter's severed head through the streets shouting, ‘I avenged my honor.’”

But Islamic scripture in no way condones such actions, Carroll said.

"People have their own cultural nuances and norms from before they got their religion," he said. "This is not Islamic culture."

Regardless of whether religion itself is to blame, Gartrell said it is important that society recognizes the case as having a cultural element, just to prevent similar crimes in the future.

"That culture is so different," Gartrell said. "If people had been more educated about it, they would have known that when the girls told people, 'Dad wants to kill me' — they were serious."

Many of the threats against Sarah and Amina Said were known to their friends and classmates.

High school friends told the Dallas Morning News that the girls sometimes came in with welts and bruises, which they confided were inflicted by their father. One time, Yaser Said reportedly went into one daughter's bedroom waving a gun and making threats on her life.

After he threatened to kill one daughter in December 2007 — documented in text messages Sarah Said sent to a friend — the girls and their mother, Patricia, fled from their home in Lewisville, Texas, to Tulsa, Okla. But the mother soon had a change of heart and went back, leading to the tragedy on January 1. Some, including Gartrell, believe the mother may even have been complicit in the murders.

Dr. Phyllis Chesler, author of several books, including "The Death of Feminism: What's Next in the Struggle for Women's Freedom," said that the case fits the description of an honor killing.

"The premeditation, the family collaboration, and the particular rules (set for the girls) make this consistent with an honor killing — not just domestic violence,” she said.

She said she hoped that calling the case an "honor killing" might indicate a shift in attitude at the FBI.

"I think this may suggest that law enforcement is beginning to realize that they may have to treat these incidents differently if they are to either prevent or prosecute," Chesler told FOXNews.com.

She noted that the United Kingdom has a special police unit to deal with “honor-related violence,” and said that she hoped that the situation in the U.S. does not get to the point where that becomes necessary.

But an FBI spokesman played down the significance of the listing, saying that the change on the wanted listing was simply due to more information coming out about the case since it was first listed and that it shouldn't matter what the case is called.

"We're just looking at how do we find the guy?" said FBI special agent Mark White, media coordinator in the bureau's Dallas office.

Irving Police Department Public Information Officer David Tull agreed. "We just look at the facts. The man killed his two daughters. This is a domestic violence, multiple-capital murder case."

Tull said that, unfortunately, there have still been no sightings or major leads — a fact that distresses Gartrell.

"I'm very upset about it," said Gartrell, who argues that the case needs special consideration. "This is not a typical murder case. When a family member murders another family member to protect [the family] name — that's different."

Click here to see the FBI's Wanted poster for Yaser Said.