CHAPEL HILL, N.C. (WTVD) -- ABC11 is learning new details about the investigation into the Aug. 28 shooting at UNC-Chapel Hill that left a professor dead in an academic building in the heart of campus.
Orange County District Attorney Jeff Nieman, the top prosecutor in the case, confirmed on Wednesday that the gun used to kill UNC faculty member Zijie Yan has not been recovered. He said authorities continue to search for it, three months after the shooting, as part of their investigation.
Nieman couldn't comment specifically about Tailei Qi, the graduate student charged with murder in Yan's death -- or on the case particulars -- but said he's generally concerned about access to firearms for people with mental health issues.
"I'm very concerned about people, the ease of access to acquiring firearms for people with mental defects, with mental health concerns," Nieman said.
Last week, an Orange County Judge ruled that Qi was unfit to stand trial, meaning he would be transferred to a facility for treatment and rehabilitation with the hopes he could stand trial at a later date. In ABC11's sit down, Nieman drew a distinction between that ruling -- which is an indicator of Qi's current mental state -- and the question of Qi's mental state at the time the crime was committed.
"Someone could be mentally capable of committing the crime, have the requisite mental intent to commit the crime, but then at a later time when they come to court, not be mentally fit for trial," Nieman said. "And the reverse could be true."
Nieman said the issue of Qi's competence during the crime has not yet been decided and could go either way. If he's able to be rehabilitated at the current facility and stand trial, that issue could be taken up.
In the wake of last week's ruling, ABC11 reached out to the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) to learn more about the laws surrounding mental health, and how that factors in when purchasing a gun.
The agency said mental health concerns and mental illness, in general, wouldn't stop gun buyers from completing a purchase, provided they were never ruled mentally unfit to have a gun by a judge in court. In fact, they sent the only form gun buyers are required to fill out when purchasing, which includes just one, yes-or-no question about mental health: "Have you ever been adjudicated as a mental defective OR have you ever been committed to a mental institution?"
If the answer to that is no, the ATF said mental health concerns can't stop the purchase on their own.
Nieman says a lack of universal background checks makes the issue even trickier.
"It's not uncommon for people who are not legally able to get a gun -- they can get it because they don't have to pass a background check first," he said.