It refers to the shooting incident in which Lu Gang, a doctoral student from China studying at the University of Iowa in the United States, shot and killed three professors and vice president Heinkele, and Shanlinhua, an China student who received his doctorate with Lu Gang. After shooting five people, Lu Gang immediately shot himself on the spot. This incident shocked China and the United States at that time. The police haven't reached a formal conclusion about the murderer's motive for shooting, but according to some media reports, the direct cause of shooting may be that Shan Linhua won the highest scholarship for doctoral thesis instead of Lu Gang. Another view is that the reason for the shooting incident may be that Lu Gang, who worked hard for six years to get his doctorate, could not get a decent job he deserved to make a living. He decided to commit suicide and take extreme revenge for social injustice.

In fact, the root cause of the Lu Gang incident is related to Lu Gang's own mentality.