I think the pilot implied that Trudy's murder triggered Monk's obsessive–compulsive disorder (OCD), which let to him having to leave the police force. But the episode Mr. Monk and the Marathon Man ...
In one of the final episodes of Monk: Why would Mr. Monk no longer require the services of Natalie Teager?
In Mr. Monk and the Three Pies we meet Adrian's brother Ambrose. When Captain Stottlemeyer comes to Ambrose's house Ambrose gives him a cup of coffee with a number 6 on the mug. Adrian explains that ...