Sgt. Jerry Martinez is one of Vic's commanding officers at the Fort Baxter Air Base. Martinez is one of the first characters introduced in the game, giving Victor the game's first missions.
Martinez does not take his position seriously and is generally a man of loose morals as can be seen when he is watching a Candy Suxxx animal porn movie. In the first mission of the game, Martinez orders Victor to get a shipment of drugs for him and hide them in the barracks. Later, he tells Victor, who is very uneasy about housing the drugs, that he will collect the marijuana once Victor picks up his "girlfriend" (a prostitute). When Victor arrives at Fort Baxter however, he is confronted by a drill sergeant who informs him that they found the drugs and question him about the prostitute in his car. Victor is given a dishonorable discharge from the Army. He later betrays both Vic and Phil when a bunch of gangsters attacked him severing relations between Vic and Martinez. He makes a deal with the Mendez brothers to oversee their shipment of cocaine arriving into Vice but it is ambushed and stolen by Victor and Lance. He later kidnaps Vic's girlfriend Louise and beats her savagly and leaves her with his men.
Victor kills Martinez at the end of the game on top of Diego Mendez's penthouse (along with Diego) and gets his revenge before he can even have time to confront Martinez on his issues with him.
His conceptual drawings (which were drawn before the games release) depict him as a sinister and villinous marine. However, his in-game character depicts him as a rather bafoonish sociopath whose only good with causing conspiracy.
Martinez is voiced by Felix Solis.