Brother, he died in his office

You're telling me someone walked into a heavily guarded police station, killed the boss with a gunshot which no one heard and then calmly walked out of the heavily guarded police station?

He killed himself, people with genius intellect can't handle pressure too well, they are so used to everything going in their favour, and when they find out practical life is different from studies (where your destiny is in your own hands), they can't deal with the anxiety and commit suicide.