I am reminded that we never found out the motive of the murderer who massacred 58 people in Las Vegas in 2017. Six years afterward, there was a suggestion that he might have been angry at the casino, but they still don't know for sure and will never know. Only in fiction do murderers always have a clear idea of who they want dead and why. When I think about local murders, the "motive" is usually that someone was drunk, high, or psychotic, and angry at a friend or relative.
@Julie a student spent most of the day in our library that day...a family member was there and was OK but it took some time to find out from the hospital. Unpleasant colleague wanted to send student back to class. I said no.
@mtechman What is wrong with some people?!