Was it a dispute over a parking space or something more sinister that prompted the shooting death of three students in an apartment near the University of North Carolina at Chapel Hill campus?

Police said “an ongoing neighbor dispute over parking” might have been a factor in the shootings Tuesday evening but said they weren’t dismissing the

possibility of a hate crime.

The victims — a newlywed couple and the bride’s younger sister — were shot in the head, sources told CNN affiliate WRAL.

Their families have said they believe the shootings were motivated by hate, and the suspect had threatened the three before, said family spokeswoman Linda Sarsour. The nature of the previous threats was unclear.

All three of the victims, Deah Barakat, 23, Yusor Abu-Salha, 21, and Razan Abu-Salha, 19, were Muslim. And given their religion and comments the alleged shooter apparently left on a Facebook page, many social media users wondered what role the victims’ faith may have played.

The 46-year-old suspect, Craig Stephen Hicks, has been charged with murder.

At a news conference Wednesday afternoon, his wife said she was “shocked” by the killings and offered condolences to the victims’ families.

“This incident had nothing to do with religion or the victims’ faith, but in fact was related to the longstanding parking disputes that my husband had with the neighbors,” Karen Hicks said.

Rob Maitland, her attorney, said the shooting “highlights the importance of access to mental health care services.”

He declined to provide any details about the suspect’s mental health history, but said, “obviously it’s not within the range of normal behavior for someone to shoot three people over parking issues.”

The father of the female victims, however, told a local newspaper that he was sure that wasn’t true.

“It was execution style, a bullet in every head,” the women’s father, Mohammad Abu-Salha, told the News & Observer in Raleigh. “This was not a dispute over a parking space; this was a hate crime. This man had picked on my daughter and her husband a couple of times before, and he talked with them with his gun in his belt. And they were uncomfortable with him, but they did not know he would go this far.”

Suzanne Barakat, Deah’s older sister, also told reporters her family wants investigators to treat the case as a hate crime.

“We are still in a state of shock and will never be able to make sense of this horrendous tragedy,” she said. “We ask that the authorities investigate these senseless and heinous murders as a hate crime.”

Police: ‘We will exhaust every lead’

The Council on American-Islamic Relations called for police to “address speculation about a possible bias motive,” and the Muslim Public Affairs Council is requesting a federal investigation “if the motives of the shooter are confirmed based on his previous social media posts.”

That’s a possibility police are considering.

“Our investigators are exploring what could have motivated Mr. Hicks to commit such a senseless and tragic act,” Chapel Hill Police Chief Chris Blue said. “We understand the concerns about the possibility that this was hate-motivated, and we will exhaust every lead to determine if that is the case.”

Ripley Rand, the U.S. attorney for the Middle District of North Carolina, said Wednesday that there was no federal investigation underway, and the incident appeared to be isolated rather than part of an organized campaign against Muslims in the state.

Police are examining the suspect’s computer to see if they find anything indicating bias against Muslims or any intent to carry out an Islamic or religious-bias attack, according to a law enforcement official briefed on the investigation.

So far, nothing has turned up to indicate a hate crime, the official said.

The FBI is assisting police, who are leading the investigation.

“The Chapel Hill Police Department has requested the assistance of the FBI to process evidence in a triple homicide investigation,” the FBI said in a statement. “It is standard practice for our state and local law enforcement partners to enlist the expertise and resources of the FBI as needed.”

Official: Dispute started over parking space

According to the law enforcement official briefed on the investigation, Tuesday’s altercation started after Hicks found a car belonging to one of the victims in what he claimed was his parking space. Then Hicks went to the victim’s condo and shot all three people in a confrontation.

Hicks turned himself in to police Tuesday night and is being held in the Durham County Jail without bond. He is cooperating with investigators, police said Wednesday morning.

Hicks has no criminal record, the official said.

His wife told reporters he had been studying to become a paralegal.

He told police that he liked guns and visiting shooting ranges, but had stopped going because of the cost, the official said.

Focus on possible Facebook post

Word of the case spread rapidly on social media.

The hashtag #chapelhillshooting and #MuslimLivesMatter quickly topped Twitter’s trending topic early Wednesday morning.

Many posted what they said were photos of the victims.

In one post widely shared online, Hicks, who claimed he is an atheist, allegedly wrote: “When it comes to insults, your religion started this, not me. If your religion kept its big mouth shut, so would I.”

CNN couldn’t independently confirm the authenticity of the post or his Facebook page.

Community shaken

The condominium is home to many university students. Tuesday night, friends and family members gathered, crying or comforting each other, as they waited for word from officers.

“It’s been hours. Just tell me if he’s alive,” one man cried out.

An officer tried to calm him down. “Give us more time,” he said.

A prayer service and vigil in memory of the slain students was scheduled for Wednesday evening, the University of North Carolina at Chapel Hill said.

The shooting has left the community shaken, Chapel Hill Mayor Mark Kleinschmidt told CNN’s “The Situation Room.” Chapel Hill is a safe place for Muslims and people of all faiths, he said.

“We’re all struggling to understand what could have motivated Mr. Hicks to commit this crime. … It just baffles us,” he said.