Jeffrey Cross is Carl's friend and neighbor who pursues a rapping career in the mold of 1990s West Coast gangsta rappers. Although he is not a member of the GSF, he assumes a "gangsta" nickname, OG Loc, and commits minor crimes such as joyriding specifically to get sent to jail and therefore improve his street credibility. However, Loc's rapping is terrible and even his friends find it unbearable to listen to.
In The Introduction, Sweet tells Loc to abandon his fantasies about being a gangster and instead to enter college and make something of himself, and in-game dialogue suggests that Smoke also believes that Jeffrey is more suited to go to college. However, he refuses, saying that rapping is his true calling. The game suggests that while in prison, Loc engaged in homosexual activities with Freddy, an inmate, as mentioned in dialogue when CJ and Loc pursue and kill Freddy shortly after Loc's release from jail. After being paroled, Loc is given a job as a janitor (which he refers to as a "Hygiene Technician") at the local Burger Shot.
While working at the restaurant, OG Loc asks CJ to aid him in jumpstarting his music career by stealing some music equipment from a beach party and a rhyme book from Los Santos hip-hop star Madd Dogg. Loc also has CJ derail Madd Dogg's career further by killing his manager, who, Loc believes, was using his influence to keep Loc's career from taking off. Shortly afterwards, Loc quits his job, having decided that he'd rather violate his parole and return to jail than work at a job that "ain't gangsta". However, as CJ's actions send Madd Dogg into decline and depression, Loc is afforded the opportunity to rise to stardom. After CJ's friends betray him and he is exiled from Los Santos, Loc becomes a mainstream success with help from his agent, Big Smoke.
Later in the game, after CJ saves Madd Dogg's life and is rewarded with a position as his manager in Las Venturas, the two pursue OG Loc to reclaim Dogg's rhyme book. After a lengthy chase, the two men corner Loc, who agrees to give up rap and leave them alone from then on.
It is a running gag that his name "Oh-gee Loc" frequently is mispronounced; radio talk show host Lazlow calls him "Oglock", music DJSage talks about "Oge Loke", and his rival Madd Dogg rues the day that his number one position was taken over by "Loc OG". One of CJ's girlfriends calls him "OG Joke."
In Grand Theft Auto IV, the player can find CD cases of an album entitled Str8 From Tha Streetz by OG Loc, with his picture on the cover.