Ashley is Alexis Castle's first serious boyfriend and first love.
In 3XK (episode 3.6), Alexis discovers she has a secret admirer, who turns out to be Ashley.
He has a pet rat, named Theodore, who he treasures and leaves in Alexis' care in Murder Most Fowl. Alexis is distraught when she loses Theodore, but Ashley forgives her saying while he does care about his pet, he cares for her more.
Castle meets Ashley's parents in Close Encounters of the Murderous Kind and is concerned when Alexis tells him Ashley's father is an economics professor who dislikes fiction stories like those Castle writes. Castle invites them to his loft for dinner so they can get to know each other, and even though he skips out early to help Detective Beckett solve a murder, Ashley's parents find him so interesting that they ask to join Castle, Alexis, and Ashley on a camping trip.
Alexis breaks up with Ashley briefly in Pretty Dead, fearing he will resent her because she doesn't want him to go Stanford University for college, even though it is his first choice college. However, Ashley changes his mind and decides to go, thinking he can make a long-distance relationship with Alexis work. He and Alexis get back together, and much to Castle's chagrin, she decides to graduate from high school early so she can join him at Stanford in the spring. Their plans are foiled when Alexis doesn't get accepted and due to the time difference and Ashley's busy schedule, their relationship deteriorates. The final straw comes when Ashley is too busy to talk to Alexis when her father and grandmother are held hostage during a bank robbery in Cops and Robbers. Alexis breaks up with him for good out of frustration that he is never there for her.
He is played by actor Ken Baumann.