RALEIGH, N.C. — Relatives of the three Muslim college students killed in North Carolina are pressing for hate crime charges against the alleged shooter, but legal experts say such cases are relatively rare and can be difficult to prove.

Police in Chapel Hill say they have yet to uncover any evidence that Craig Stephen Hicks acted out of religious animus, though they are investigating the possibility. As a potential motive, they cited a longtime dispute over parking spaces at the condo community where Hicks and the victims lived.

Hicks, 46, is charged with three counts of first-degree murder in the deaths of Deah Shaddy Barakat, 23; his wife, Yusor Mohammad Abu-Salha, 21; and her sister, Razan Mohammad Abu-Salha, 19.

The FBI is now conducting a “parallel preliminary inquiry” to determine whether any federal laws, including hate crime laws, were violated.

DOZEN FIREARMS SEIZED

Search warrants filed in a court Friday showed Hicks listed a dozen firearms taken from his condo unit. The warrants list four handguns recovered from the home where he lived with his wife, in addition to a pistol the suspect had with him when he turned himself in after the shootings. Warrants also listed two shotguns and six rifles, including a military-style AR-15 carbine, and a large cache of ammunition.

The case spurred international outrage.

A news release Saturday from the 57-nation Organization of Islamic Cooperation, the world’s largest bloc of Muslim countries, said the group’s leader thanks the American people for “rejecting the murder which bear the symptoms of a hate crime.” Secretary General Iyad Madani also said the slaying has heightened international concerns about “rising anti-Muslim sentiments and Islamophobic acts” in the United States.

“No one in the United States of America should ever be targeted because of who they are, what they look like, or how they worship,” President Obama said Friday in Washington. And in New York, spokesman Stephane Dujarric said United Nations Secretary-General Ban Ki-moon was “deeply moved” by the thousands attending the victims’ funeral this past week.

Jordan’s Embassy in Washington said its ambassador visited the families Friday. Yusor Abu-Salha was born in Jordan, as where her parents. The younger sister was born in the U.S.

Family members say all three were shot in the head, though police aren’t saying exactly how the victims died.

“This has hate crime written all over it,” said Dr. Mohammad Yousif Abu-Salha, addressing the funeral service Thursday for his daughters and son-in-law. “It was not about a parking spot.”

To win a hate-crime conviction, however, legal experts say prosecutors would have to prove Hicks deliberately targeted those killed because of their religion, race or national origin.

North Carolina does not have a specific “hate crime” statute, though its laws cover such acts of “ethnic intimidation” as hanging a noose, burning a cross or setting fire to a church.

ALREADY FACING STIFF PENALTIES

Colon Willoughby, who recently retired after 27 years as the top prosecutor for North Carolina’s largest county, said he could remember only a handful of such ethnic intimidation cases. The reason, the former district attorney for Wake County says, is that the defendants often already faced potential charges with stiffer criminal penalties than the comparatively light punishments carried by an ethnic intimidation conviction.

Hicks will likely face either the death penalty or life in prison if convicted of murder charges.

Hicks, who was unemployed and taking community college classes, posted online that he was a staunch advocate of Second Amendment rights. Neighbors described him as an angry man in frequent confrontations over parking or loud music, often with a gun holstered at the hip. His social media posts often discussed firearms, including a photo posted of a .38-caliber revolver. An avowed atheist, Hicks appeared critical of all faiths in Facebook posts.

Durham County District Attorney Roger Echols said he hasn’t decided whether to bring any ethnic intimidation charges.