A University of North Carolina PhD student shared several posts on social media complaining about his academic adviser before allegedly shooting him dead in the science lab and plunging the Chapel Hill campus into lockdown. Tailei Qi, a 34-year-old graduate student majoring in applied physical sciences, was arrested on Monday and charged with first-degree murder in the killing of faculty member Dr Zijie Yan. The motive for the shooting remains unclear but his account on X, formerly known as Twitter, reveals he had complained grumbled about his head of lab in the lead-up to the shooting. In other posts, he also railed against hard work, aired his grievances with some “girls and tattletales” and complained about bullies in the US. “Bully in america seems to be a problem. It often comes with people not stopping them at the first time,” he wrote in one bizarre post in August 2022, reviewed by The Independent. “Explanation is not a solution but makes them feel others will plead them every time they raise a problem, making them voyeur to find an excuse day and night.” Two weeks later on 18 August 2022, he tweeted about his “PI” – an abbreviation for his head of lab – handling “these girls and tattletales”. “Just have a talk with my PI and get his promise. He should have more experience to handle with these girls and tattletales,” he wrote. “Then, we can just get ourselves out of these stupid topic. Let’s just focus our attention on nature.I won’t change anything if not necessary.” Two months later in October 2022, he referred to his PI again and an unidentified “group of people”. “Both the group of people to say I am lazy and that to prove me working hard instead of telling me that are trying to consume my privacy. I judge their motivation is only to tell my PI then control me by taletelling,” he tweeted. “But it’s weird when I talked about it with my PI, he said no people spoke to him about that. so it’s nothing but some voyeurism for these people?” Yan headed up the Department of Applied Physical Sciences and physical chemistry group the Yan Research Group, which Mr Qi joined when he began his graduate program at UNC in 2022. In other online posts, Mr Qi addressed a mystery woman who he vowed to “just let her go” and his exhaustion with his workload. “I used to walk [sic] 80+ hours per week and I feel relaxing and energetic. Now I only work 60+ hours per week and I feel tired,” he wrote in one. In a post in July 2022 – before he is believed to have started at UNC that fall – he posted a cryptic message calling his treatment by an unnamed boss “disgusting”. “Just feel my privacy was insulted. When I work, I will think I was showing the boss I am working instead of interests, devaluing the meaning of my work,” he wrote. “That’s so disgusting. Self-respect block me from working. Then it takes pains to convince myself what I do is just because I like.” In another post that same month, he wrote that “only work with no play makes Jim a dull boy”. In one of his most recent posts in early August 2023 – just weeks before the shooting – Mr Qi issued an appeal to meet people at the college. “I would like to make some new friends. I am a second-year PhD student, interested in nanoparticle synthesis, optical trapping, self-assembly, spectra analysis, and ML,” he said. “a bit stupid in daily trifles, very enthusiastic talking about research. Reach me if inerest.” The Twitter account has the same name and the same image as both Mr Qi’s bio and the person of interest sent out by police during the brief manhunt. It describes him as “Graduate student @UNC, engaged in light-matter interaction and related materials”. Mr Qi previously studied at Wuhan University before moving to the US from China and studying at Louisiana State University. He joined the Yan Research Group at UNC in 2022. At around 1pm on Monday afternoon – just days into the new term of the second year of his PhD studies – Mr Qi allegedly entered the science lab at the UNC’s Chapel Hill campus and shot and killed Yan. Law enforcement arrived on the scene around two minutes later and the campus was plunged into lockdown, with officials warning that “an armed and dangerous person” was at large. The wrong person was briefly arrested after the unsuspecting individual missed the shelter-in-place alerts. Soon after, the UNC Police released an image of Mr Qi, calling him a person of interest and warning the public that “if you see this person, keep your distance, put your safety first and call 911”. Around three hours on from the shooting, police confirmed that a suspect had been arrested near a residential area 10 minutes away from campus and the lockdown was lifted. The gun is yet to be recovered, police said. The motive for the attack remains unknown at this time. “To actually have the suspect in custody gives us an opportunity to figure out the why and even the how, and also helps us to uncover a motive and really just why this happened today. Why today, why at all?” UNC Police Chief Brian James said in a press conference on Monday. “And we want to learn from this incident and we will certainly work to do our best to ensure that this never happens again on the UNC campus.” Read More UNC shooting – latest: Motive remains unknown after shooter kills faculty member in Chapel Hill He moaned about work, ‘bullies’ and his head of lab online. 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