Giovanni Gilberti is a mechanic of his family's business, Gilberti & Sons Auto Shop. Angela Rizzoli is good friends with his father and likes Giovanni, which is why she often tries to make her daughter, Jane to like him. He and Jane also went to high school together.
In "Sailor Man", Maura Isles becomes interested in him for sex because of his body, which Jane tries to discourage Maura of, saying that she will not Giovanni's type, even if just for sex. This later proves true when Giovanni tries to pursue a serious and weird relationship with Maura, who soon realizes what is so dislikeable about him. Maura finds his words and presents sweet, despite his odd fetishes, and is unable to tell him that she was only interested in sleeping with him, so she asks Jane for help. When Jane tries to turn Giovanni off with Maura's job, they fail miserably when he ends up finding it "wicked". Later, they attempt to bluntly tell him that Maura is uninterested in him but end up speechless when they find that he has pimped out Angela's car that he was supposed to just repair. Maura and Jane, instead, end up telling Giovanni that they are a lesbian couple. Giovanni confesses that he is dismayed, since he had believed that he and Maura were soulmates... then ruins the moment by telling them that he's interested in trying a threesome if they were interested.
Giovanni attends their high school reunion in "Seventeen Ain't So Sweet" and let's it subtly slip to Steve Sanner, and later Angela, that Jane is gay. During the reunion, she reconnects with Maria Korkman, a girl he used to tease about being fat, and is suddenly the new "love of his life". They spend two days going on dates with each other before she dies of a heart attack right in front of Giovanni.
Giovanni reappears in "Throwing Down the Gauntlet", delivering a package for Angela who he is helping with the campaign for Tom McGregor, Jr. Later, however, after calling Angela hot several times, he gives her a bikini costume and pretty much tells her to have a "May-December romance" with him, saying that he is lonely. When Angela threatens to send his body parts to his mother, he apologizes and just asks her for a motherly hug.
Giovanni comes back in "Built for Speed".
Giovanni seems to be a very shallow person and is not the smartest guy out there. He often calls girls "hot" and falls in love with almost every girl he likes. He also has a strange way of showing his affections, like wanting to lick Maura's face and just bluntly saying he wants to get her naked.
Angela seems quite attached to Giovanni. When Angela's car breaks down in "Sailor Man", Giovanni secretly pimps out her ride, charging her only for the parts that he had repaired, saying that Angela was good to him growing up so he doesn't want to charge her.
In "Throwing Down the Gauntlet", however, Giovanni makes a move on Angela when he becomes lonely and insecure when no girl takes him seriously. He later apologizes and asks her for a "mom hug" instead, but Angela is obviously disturbed by Giovanni's words.
Jane dislikes Giovanni but be can't seem to take a hint in season 4 and he gives Jane persuades him to give her his cell phone on she will have to seize his car for attempted drag racing. He keeps hitting on Jane but she shoots him down every time.
He has not seen since season 5.
- He owns an Alfa Romeo Spider he calls Giulietta.