The bomb was built by Warrick Tennyson. Tennyson mentions (in "Mr. Monk Takes Manhattan") that he did not recognize the man who hired him, but remembers that he had six fingers on his right hand. From the time of Trudy's death until the end of the season two, Monk believes all along that he was the intended target, with Trudy being an innocent victim. The intense guilt contributed to and intensified his nervous breakdown, his obsessive-compulsive manifestations, and his bizarre phobias. Dale reveals (in "Mr. Monk Goes to Jail") that the car bomb was actually intended for her, not him. Discovering that Trudy was the true target, Adrian is seen to be visibly affected by this news.