Legality of Computer Servalence

This employee is not a team player and he will use these things against us:

1) He has a physical Disability
2) Is Homosexual
3) Threatens the company
4) We had software application license issues

We have a application called SPECTOR installed on his PC and it records every action. We have compiled 70+ pages of proof of violates. What we want to know is if anyone has legal advice about the proof. Can we legally fire him for the recordings that were made without him knowing it? Thesepages include personal emails with sexual content. The last question is how would I approach firing him? I am just so concerned this will turn out with the cops showing up and this is so vital that we don’t have a conflict.

Thanks.