An FBI Agent who dated Detective Kate Beckett for six months. Their relationship ended when he accepted a job offer in Boston, and a bitter Kate chose to stay in New York. When dating, their favorite activities were spending weekends in a park, and ice skating at Rockefeller Center.
From the moment he meets Richard Castle, he sees him as a threat to his potentially rekindling his romance with Kate and treats him in a very cocky, superior manner.
Having known Kate longer than Castle, he is keenly aware of how her mother's murder affected her, and knows how Castle's books helped her get past the tragedy.
He appears in Little Girl Lost (episode 1.9), when he recruits Beckett to help him on what looks to be a kidnapping case, and A Death in the Family (episode 1.10), when Beckett enlists his help in interviewing a mob informant she and Castle suspect may have knowledge that will help them solve a murder. In The Time of Our Lives (episode 7.6), it emerges that he is about to get married and has invited Beckett to his wedding.
He is portrayed by actor Bailey Chase.