In unrelated but possibly related news - David Turpin, the father who kept his 13 kids in horrible conditions, worked for Lockheed and Northrup. I hope these children can somehow find the ability to cope and live a better life but can’t even begin to imagine what they went through.
Do you think there is any chance he had a security clearance? If so, and depending on the investigation type, there is a very slim chance investigators could have caught something by talking to neighbors. I wonder if it would be good for investigations to include a welfare check on applicants residences? Just a quick in person at the residence while in the neighborhood to make sure nothing sinister is going on.