- "I was in the game too long, Mike. Any morals I had died a long time ago. You're just a dumb, gullible, kid. I didn't want to share the money with you, plain and simple.... goodbye, Mike."
- ―Vinnie telling to Mike why he betrays him.
Vinnie was a criminal in Liberty City who worked for an unknown mafia family. Vinnie is the partner and boss of Mike, a formerly-homeless small-time thug. Several years prior to the game's events, Vinnie found Mike on the streets and took him in for the mafia, eventually making Mike a high ranking associate. They worked along side each other, with Vinnie as the brains of the operation.
Due to unknown circumstances, Vinnie and Mike had a plan to leave Liberty City. Behind Mike's back, Vinnie thinks very little of Mike, seeing him as nothing other then a "Stupid kid" and a pawn in his plans, regardless Vinnie continues to keep Mike at his side for a period of time, waiting and planing.
Over the years, the two earned enough money to leave Liberty City for good. However, prior to their leaving in 2000, Vinnie insisted Mike do a few more jobs for the mafia before leaving. Vinnie sent Mike to complete several favors for the mob, in order to obtain even more money. Vinnie secretly put a bomb in his car and called Mike to meet him. Mike witnesses Vinnie allegedly being killed by the car bomb, with his "remains" found in the vehicle.
After his "death", Mike wanted revenge, and works for many sources in the Liberty City criminal underworld, such as 8-Ball, the owner of a bomb shop, Jonnie, a bartender with underworld connections in Liberty City and slowly uncovers who was behind the murder. Vinnie catches wind of this and stalks Mike's leads throughout the city, even going as far as to hire mobsters and to kill people when necessary starting with Jonnie. Vinnie murders Jonnie and Mike starts working with the Yardies leader King Courtney, who Vinnie has an apparent bussiness relationship with.
After Mike finds out of King Courtney's treachery, he works with Cisco, the leader of the Columbian Cartel and at the same time Asuka Kasen, leader of the Yakuza. Vinnie once again decides to take matters into his own hands and kills Cisco at the airport. Mike finds Cisco's body almost immediately after the attack and fights off Vinnie's hired thugs and sees Vinnie's car driving off. After a short chase Mike destroys Vinnie's car and finds out Vinnie is alive after he escapes the wreck. Vinnie finally reveals his true nature and motive to Mike. This shocks and angers Mike and after a short shoot out with Vinnie and his thugs, Mike manages to overpower them and mortally wounds Vinnie. Vinnie begs for his life, but Mike suspects that Vinnie would eventually betray him again. Vinnie tries to reason with Mike that any criminal greedy enough will try to steal the money from Mike and that he will end up dead before he can reach the city limits. Mike ignores this and finally kills Vinnie.
Vinnie is shown to be a rather rude and cruel person throughout his time with Mike and often treats him harshly. When Mike asks for backup in the mission Payback, Vinnie declines and tells him not to make him regret helping him when he had nothing. Vinnie will sometimes make humorous yet cold comments towards Mike if he gets busted, likewise, Vinnie will often belittle him if he gets wasted. When Vinnie betrays Mike, he tells him that his morals died long ago and he didn't want to share the money, though if Mike is wasted earlier in Dirty Laundry, Vinnie will lament how he won't be able to spend it with him by his side.
- Jonnie (killed for attempting to find out about his "death")
- Cisco (killed for attempting to find out about his "death")
- GTA Advance
- Jump Start (Boss)
- Dirty Laundry (Boss)
- Hot Wheels (Boss)
- Ill-Gotten (Boss)
- Payback (Boss)
- Fake IDs (Boss)
- Getaway (Pager/Boss/Fake death)
- Truth Revealed (Betrayal/Killed)
- Vinnie, along with Dimitri Rascalov if the Revenge ending is chosen, is the only main antagonist not killed in the final mission.
- Through the main story, is heavy implied that Vinnie was known and disliked by several characters and bosses. For example, 8-Ball states that Mike was the only person "who gave a damn about him", and he "should be considered lucky" about that.
- Vinnie used to hang out with prostitutes, as one of them revealed "he was a good tipper" in the mission Ill Repute.
- He is very similar to Vincenzo Cilli from GTA LCS. Both are antagonists in their respective game (although Vincenzo wasn't the main antagonist), both are friends with the protagonist early at the game, later both of them betray the protagonists. Coincidentally, both of them are named Vinnie.