The follow up to this story began a few days later when I got a call to report to the division chief's office and to not let anyone know where I was going. When I got there, he told me to come in and close the door.
He began asking me about the flying mouse incident and the guy (we'll call him "Roger" here) in general. He was concerned about Roger's well known temper, and during our discussion he asked me if I knew if Roger owned a gun. When I said I didn't know, he asked me if, since I sat next to him, I could find out. I agreed.
A week or so later I casually mentioned to Roger a few friends and I were going to the gun range that weekend. I then asked if he liked to shoot, and if he had any guns. He replied, "No, I don't have any guns, but I do collect swords."
The next day I got on the division chief's calendar and told him what I'd found out. He looked a little disconcerted about the swords, but was viable relieved when I told him Roger did not own a gun. He thanked me for my sleuthing activities.
As I was leaving, I told him I wasn't personally concerned for my safety with Roger. When he asked why, I told him I knew for a fact there were at least three people in the office who I could out run. I said, "I don't have to outrun Roger, just the slowest person in the office." He was not amused.