Does the Govt have a DNA/Biometric Database on us all & the RNC W/Tom Renz

My brother pointed out an interesting fact to me - the FBI stated that the shooter had no ID so they identified him using DNA and biometric data. This is interesting because he was also reported to have had no criminal record. How then does the FBI have access to his DNA and biometric data? There are several possibilities but I think it's fair to ask whether the government is keeping a database on all of us and, if so, how... because wouldn't that be illegal?