"It was execution style, a bullet in each head," the father of two of the victims, psychiatrist Mohammad Abu-Salha, told the News and Observer.
He said the gunman's underlying animosity towards his daughters and son-in-law was based on their religion and culture. He said his daughters "dressed in Muslim attire.".
He said: "This was not a dispute over a parking space; this was a hate crime. (Police said that initial investigations pointed to a parking dispute, see report on right).
"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."
Craig Stephen Hicks, 46, is alleged to have shot Mr Deah Shaddy Barakat, 23, his wife, Ms Yusor Mohammad, 21, and her sister, Ms Razan Mohammad Abu-Salha, 19, in their apartment.
Hicks, who lives nearby, turned himself in and has been charged with three counts of first-degree murder.
Mr Deah, the son of Syrian immigrants, was a second-year student in dentistry at the University of North Carolina (UNC), while Ms Yusor was planning to begin her dental studies in August.
Ms Razan was a student at North Carolina State University, according to the UNC newspaper, the Daily Tar Heel.
Mr Deah's sister asked that authorities investigate the three "senseless and heinous murders" as a hate crime.
A Facebook page, believed to belong to Hicks, showed dozens of anti-religious posts, including one calling himself an "anti-theist", saying he has a "conscientious objection to religion," and other memes denouncing Christianity, Mormonism and Islam, reported AFP.
His page also showed a photo of a loaded revolver, alongside a video of a puppy and a promotional clip for Air New Zealand.
One post read: "I'm not an atheist because I'm ignorant of the reality of religious scripture. I'm an atheist because religious scripture is ignorant of reality. "Given the enormous harm that your religion has done in this world, I'd say that I have not only a right, but a duty, to insult it."
Police said initial investigations indicated a dispute between Craig Stephen Hicks, 46, and his victims over parking spaces may have been the catalyst for the shooting.
It claimed the lives of Muslim students Deah Shaddy Barakat, 23, his wife, Ms Yusor Mohammad, 21, and her sister , Ms Razan Mohammad Abu-Salha, 19, in Chapel Hill, North Carolina.
"Our investigators are exploring what could have motivated Hicks to commit such a senseless and tragic act.
"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," police chief Chris Blue said.
At a news conference, Hicks' wife insisted that the shooting was only due to parking arguments and not because of any bigotry, reported the Washington Post
"I can say with my absolute belief that this incident had nothing to do with religion or the victims' faith, but in fact was related to the long-standing parking disputes that my husband had with the neighbours," Mrs Karen Hicks said.
"We were married for seven years, and that is one thing that I do know about him."
She said Hicks was studying to be a paralegal and was due to graduate this year, and described him as a champion of individual rights in many areas, including race and same-sex marriage.
She later released a statement that she was divorcing her husband.
Her attorney, Mr Robert Maitland, said there had been a dispute with the homeowners' association over parking, USA Today reported.
"It is a simple matter that has nothing to do with the religious faith of the victims," Mr Maitland said.
This article was first published on February 13, 2015.
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