[3] The suicide bomber responsible was identified as 22-year-old Xu Taoran, who had "vegetative nervous function disturbances,"[4] a disorder that can cause heart and breathing problems.
After the attack, investigators found material to make a homemade explosive device and, written on a wall near the school, a "manifesto-style rant."
Chinese investigators used physical evidence and DNA found at the scene to determine the identity of the suspect, which pointed to Xu Taoran, 22, a university dropout who had written violent screeds against parents and children.
Taoran had antisocial tendencies and had a debilitating autonomous nervous system disorder that forced him to take a leave of absence from his school, authorities said.
[6] The police discovered the materials used to make the explosives in his apartment, along with words such as "'die,' 'death' and 'destroy'" written on the walls, assumingly pointed towards children and families.