Full name: Javier Esposito
Nicknames: Javi, Espo
Relationships: Lanie Parish (ex girlfriend)
Best friend: Kevin Ryan
Departments: Special Forces, Organized Crime Task Force, Homicide
Precincts: 54th, 12th
Weapon: Glock 17
Javier Esposito is a bilingual (English and Spanish) detective who works in the homicide division with his partner, Kevin Ryan, as part of Beckett’s team. He is always ready with a sardonic comment to keep Beckett on her toes and enjoys the way Castle riles her up. He and Ryan are best friends, even though they constantly argue about obscure facts. He is disappointed when Ryan felt obligated to ask his fiance’s brother to be his best man instead of him. He is a fan of Shark Week, and it is revealed that Esposito transferred out of the 54th Precinct and has been partnered with Ryan for 3 years prior to the pilot episode.He and medical examiner Lanie Parish began a relationship they believed was a secret. However, their relationship was common knowledge to the other characters, who were playing along out of respect for their privacy, before Ryan tells Esposito that everyone knows about the relationship. Esposito reveals that he and Lanie are “taking a break” after an awkward incident on a double date.
In the season four finale, Esposito stands firmly behind Beckett as she decides to pursue the investigation of her mother’s murder in secret because they fear that there would be other dirty cops in the Precinct. This leads him to quarrel with Ryan who believes that they should come clean. After fighting with Maddox on the roof of a building, Beckett is saved by Ryan and Gates whom he had warned. Back at the Precinct, Gates suspends Beckett and Esposito for their actions. Beckett then resigns and Esposito refuses to talk to Ryan, just walking away as he tries to explain.