I suspect (and hope) we’ll find out more in the days ahead. He did understand one key aspect of operational security, though. Once a secret is known by more than one person, it’s no longer a secret. So maybe he took his motive to the grave with him.
Right now forensic specialists in Quantico are going through his computers. That's going to take a while. I'm sure the public will be debriefed on what is found, if anything's found.