The Mirror reports that he left a message on his Out-of-office alert:

"I am out of the office. Indefinitely. For urgent enquiries, or indeed any enquiries, please contact someone who is not an insane psychopath."For escalation, please contact God, though suspect the devil will have custody. (Last line only really worked if I had followed through…)"


If that doesn't prove it was premeditated, then what does. Sounds like a rather disturbed guy...