|Appearances||"Cops & Robbers"|
|Portrayed by||Frank Birney|
Father Sean McCaskey was a Catholic priest.
When Tanya Brandt sought to escape from her abusive husband, she faked the deaths of her and her son Connor in a boating accident; Father McCaskey was one of the few people aware of the truth, as he officiated at their funeral.
He also served as the 'middle-man' to communicate between Tanya and her mother, Agnes Fields, to prevent Ron finding her; Tanya sent letters to her mother to Father McCaskey, who took them to a safe deposit box that Agnes had in a local bank, Father McCaskey posing as Agnes's dead husband to avoid attracting attention to his presence.
When Ron Brandt realized that his wife and child were alive and set up an elaborate plan to access the contents of the safety deposits box, the team were able to deduce Father McCaskey's role in the plan in time for him to provide Castle and Beckett with Tanya's new address, allowing them to alert the local police to Ron's intentions and stop his attempt to take his son.