  fbi special agent john jay doggett is a fictional character in the fox science fiction television series the x-files. with his fbi partners dana scully (season 8) and monica reyes (season 9), they work on the x-files office together, which is concerned with cases with particularly mysterious or possibly supernatural circumstances that were left unsolved and shelved by the fbi. john doggett is played by robert patrick. doggett was a main character from the eighth to ninth seasons (2000â2002), replacing david duchovny's character fox mulder. doggett appeared in the opening credits and every episode from the season eight premiere to the series finale. doggett made his first appearance in the 2000 episode "within". doggett served in the united states military from the 1970s to the 1980s. later he started working for the new york police department, he was eventually promoted to detective. after his son's death, he got a job in the fbi. he started to work for the criminal investigations division. in 2000, he was assigned to the x-files office, after the disappearance of mulder. the introduction of doggett was met with mostly positive reaction by critics, while getting more mixed response from longtime fans of the series. == character arc == doggett served in the united states marine corps in the 24th marine amphibious unit from 1977-1983. his final rank was sergeant (e-5). while serving in the military, he became good friends with fellow marine knowle rohrer. from 1982-1983, doggett played a role in the multi-national peacekeeping force for lebanon development. doggett retired from the u.s. marine corps with commendations after being wounded in the line of duty. after gaining a juris doctor and a masters degree in public administration from syracuse university, doggett went on to work for the [[new york 
Fictional_FBI_agents Fictional_United_States_Marines Fictional_characters_introduced_in_2000 Fictional_detectives Fictional_police_officers Fictional_sergeants The_X-Files_characters