I don't think it is weird at all. If he isn't a criminal, why would he be fingerprinted? At least in my state, you don't get fingerprinted at birth and you don't get fingerprinted when you go to school.
My whole life, I was never fingerprinted until I took the bar exam. I don't think it's unusual at all for a person not to have fingerprints on file with the government. Why would they? Why would you want that?
You get fingerprinted when you apply for a CCW, to get a security clearance, to get bonded, when you are arrested, etc.
Why do they need fingerprints at all? If this guy was an established member of the VT engineering department community, someone knew him and could ID him. Unless he isn’t a member of the community at all...
There’s not going to be a trial - the perp is dead. Why all this effort to gather evidence?