Amid national discourse on whether or not the shooting of three young Muslim students in Chapel Hill, N.C. was a hate crime, the Federal Bureau of Investigations (FBI) has decided to open an inquiry.

According to the Washington Post, the feds announced their decision Thursday, two days after Craig Stephen Hicks, 46, shot and killed Deah Barakat, 23; his wife, Yusor Abu-Salha, 21; and her sister, Razan Abu-Salha, 19. Hicks was a neighbor to the three young students at a Chapel Hill apartment complex and has been known to get far too intense over his parking spot.

Hicks turned himself in Tuesday night and has been charged with three counts of first-degree murder, though his motive has yet to be nailed down.

"The FBI has also opened a parallel preliminary inquiry to determine whether or not any federal laws were violated related to the case," the FBI said in a statement.

On his Facebook page, Hicks identifies as an atheist, but he also reportedly has posted or endorsed posts openly mocking and criticizing organized religion. Still, other residents at the apartment complex have seen Hicks be a little too overprotective of his parking spot.

Michael Nam, a recent graduate from the University of North Carolina (UNC) - Chapel Hill, told BBC News he once got into a verbal altercation with Hicks. After parking one day, Hicks came outside with a gun on his hip to meet Nam, who said he relented out of annoyance and not fear.

But Hicks may have also just made people feel "uncomfortable and unsafe" in general, according to another one of his neighbors.

"I have seen and heard him be very unfriendly to a lot of people in this community," Samantha Maness told the New York Times.

She said Hicks would call to have cars towed if he so much as did not recognize the vehicle. He was also a frequent noise complainant, Maness told the Times, and "was definitely aggressive, and he spoke harshly when he was upset."

Yusor and Razan's father, Dr. Mohammad Abu-Salha, told the Raleigh News and Observer Hicks is guilty of a hate crime due to "execution style" murders. Unnamed sources have previously told multiple media outlets each victim had a gunshot wound in the head, but the person who called 911 says there more than just those three shots.

Remaining anonymous, she told the Observer she was in the hallway when she heard about eight shots go off amid screams, followed by silence and then three more gunshots. Hicks' wife Karen, who by law cannot testify against her husband, said the shooting was over a parking spot.

"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," Mohammad Abu-Salha told the Observer. "Honest to God, [my daughter] said, 'He hates us for what we are and how we look.'"