Chapel Hill police suggested that Craig Stephen Hicks, 46, may have been involved in a long-running dispute over parking with the victims but did not offer a clear motive for the shooting.
A Facebook page that appeared to belong to Hicks, however, revealed a strong anti-religion bias and a love of guns. Here are some other insights into Hicks' politics gleaned from his social media profile.
He's a self-professed "anti-theist"
The lead photo on Hick's Facebook page professed his belief in "anti-theism" and stated that he wants "religion to go away."
"I don't deny you your right to believe whatever you'd like; but I have the right to point out it's ignorant and dangerous for as long as your baseless superstitions keep killing people," the text in the photo read.
Religious scholar Reza Aslan explored a new wave of "anti-theism" among atheists in a piece for Salon published in November. He argued that anti-theists like Richard Dawkins and Sam Harris respond "to religion with the same venomous ire with which religious fundamentalists respond to atheism." Aslan also cited a poll showing that about 85 percent of atheists do not subscribe to anti-theism.
Hicks quoted Dawkins at length on losing respect for "Abrahamic religions" after the 9/11 terror attacks in a 2012 post.
“My respect for the Abrahamic religions went up in the smoke and choking dust of September 11th," the post read. "The last vestige of respect for the taboo disappeared as I watched the 'Day of Prayer' in Washington Cathedral, where people of mutually incompatible faiths united in homage to the very force that caused the problem in the first place: religion. It is time for people of intellect, as opposed to people of faith, to stand up and say 'Enough!' Let our tribute to the dead be a new resolve: to respect people for what they individually think, rather than respect groups for what they were collectively brought up to believe.”
It's possible that Hicks recently gravitated to anti-theism. A 2011 post showing what Hicks said was an award he received at work which described him as an "ordained deistic minister."
He loved guns and railed against gun control
Last month, Hicks posted a photo to Facebook of a revolver he said he owned:
His Facebook profile also listed several gun-themed pages among his "likes," including a page called "hypocrisy and stupidity of gun control advocates."
Back in 2011, Hicks posted his reaction to the Tucson, Arizona shooting in which 22-year-old Jared Lee Loughner killed six people and wounded 11 others, including former Rep. Gabby Giffords (D-AZ).
"I guess after the horrible tragedy early this week in Arizona, all Glock pistols will officially be labeled 'assault weapons,'" he wrote. "While I never cared for Glocks personally, it stinks that anyone would blame a firearm rather than the operator of such firearm for such a terrible act. I think I'll start blaming McDonalds for my weight problem, Christianity for the Ku Klux Klan, and Islam for terrorism."
He's a gay rights advocate
Hicks declared his support for marriage equality and the LGBT community in general in several posts on his Facebook page over the years.
"I am not gay, lesbian, bisexual, transgender, pansexual, intersex, or asexual," one recent post read. "I just support this crazy thought that everyone should have equal rights."
He's a loud critic of the religious right
Many of Hicks' posts focus on the separation of church and state and mock the religious right for "defying our Constitution."
"Seems an overwhelming majority of Christians in this country feel that the Muslims are using the Ground Zero Mosque plans to'mark their conquest,'" he wrote in 2010. "Bunch of hypocrites, everywhere I've been in this country there are churches marking the Christian conquest of this country from the Native Americans. Funny thing is the Christians did that while defying our Constitution, and got away with it!!"
Hicks often quoted former Presidents James A. Garfield and Ulysses S. Grant on the need to protect the separation of church and state, especially when it came to taxpayer dollars. He also drew attention to adoption of "In God We Trust" as the national motto in the 1950s along with the addition of "under God" to the pledge of allegiance that same decade, calling it "propaganda."
He's no Mitt Romney fan
Hicks' Facebook posts suggested that his views lay mostly on the liberal side of the political spectrum. His "likes" include a page called "Mitt Romney sucks," "dogs against Romney" and "liberals against conservative propaganda."
He also waded into the debate over Obamacare in a post just days before the 2012 presidential election. Hicks related how his wife's friend, an employee at a local bank, was told that if President Obama won the bank would drop its employees' health insurance.
"They will opt out and pay the penalty instead of insuring their employees," he wrote. "I'm really getting tired of this crap, and either way will never deal with this company again, not that I did before."