NYPD Detective Kevin Ryan works alongside Esposito as part of Beckett’s investigative team. He began his career working Narcotics squad but jumped at the opportunity to work Homicide. Ryan is charming, quick on his feet, and has a wealth of obscure knowledge. Always contributing a random fact or some unique piece of insight, he is a focused and invaluable detective. Recently engaged to his longtime girlfriend Jenny, he is extremely loyal both in his personal and professional life. Though he often pokes fun at his co-workers, Ryan is has no problem admitting his own shortcomings. He is a dedicated professional, who often enjoys having Castle around, but will always go above and beyond to bring criminals to justice.