He is Tony Soprano's protégé and a member of the DiMeo crime family, rising from associate to captain over the course of the series.

The character, Christopher, is a volatile, impulsive, and unpredictable young man, frustrated by his perceived lack of progress in the Mafia business.

His violent behavior often causes friction between him and the rest of the North Jersey Mafia, which is especially troublesome for Tony Soprano, who attempts to guide Christopher towards becoming a major leader in the business.

Tony trusts Christopher with sensitive tasks, such as disposing of the bodies of murdered captains Richie Aprile and Ralph Cifaretto and arranging the assassination of New York boss Carmine Lupertazzi.

This leads to friction with Paulie Gualtieri, culminating in the Pine Barrens incident and although they make an uneasy truce, they clash again on several occasions.

In the fifth season, Chris learns that Adriana has been working as an informant for the U.S. Federal Bureau of Investigation and that she wants him to go into the Witness Protection Program with her.

He grows disillusioned with Tony and frustrated with his progress in the Soprano family, and distances himself from the business by making a film and trying to become a Hollywood screenwriter.

Christopher's efforts to stay clean of drugs and alcohol cause him to spend less time at their regular haunts, further arousing Tony's suspicions.

In the episode "Cold Cuts" it is revealed that Chris grew up in the Rochelle Park section of Paramus, New Jersey next to the Westfield Garden State Plaza.

He "makes his bones" by killing Emil Kolar in order to settle a dispute with the DiMeo crime family over the Triborough Towers garbage routes.

He initially plans to place the body in a Kolar Bros. dumpster to send a warning, but Salvatore "Big Pussy" Bonpensiero convinces him to put it elsewhere as it would bring less heat to the crew.

Christopher later avenges Brendan's death as part of Tony's revenge against Junior, when he and Paulie ambush and murder Mikey out in the woods.

Chris is put in charge of the family's pump and dump scam, with Matthew Bevilaqua and Sean Gismonte serving as his subordinates.

The pair ambush Chris outside a diner and badly wound him, but he manages to kill Gismonte as Bevilaqua flees the scene.

Chris tells the crew that during his coma, he had seen himself in either hell or purgatory and warned them that Brendan and Mikey told him that three o'clock would be a significant time in their future.

As the family's newest member, he inherits a betting shop from his capo, Paulie Gualtieri and is charged with paying minimum weekly dues to him.

Elsewhere, Chris opens the Crazy Horse Nightclub in Long Branch with Furio as a partner and Adriana as the front operator.

Chris and acting capo Albert Barese fire back, killing Jackie Jr.'s friend Dino Zerilli as he tries to escape.

Eventually, Vito Spatafore carries out a contract killing on Jackie Jr. in the Boonton Projects, shooting him in the back of the head, on the orders of Ralph Cifaretto and Tony.

When the job is called off and Tony urges him to make sure it can't be traced to them, Chris has Benny Fazio and Peter "Bissell" LaRosa shoot Curtis and Johnson to death while he waits in his car watching over the hit.

Fazio and La Rosa steal back the money Chris had given Curtis and Johnson, which they believed was payment for the hit they were tasked with.

However, after he learns that Adriana has reluctantly provided information to the FBI, he turns to Tony rather than accept her plea to join her in witness protection.

Tony sends Silvio Dante to meet with Adriana, purportedly to drive to the hospital to visit Chris, but in reality, he executes her in the woods.

Chris is promoted to capo, in keeping with Tony's long-term plan to raise his nephew through the ranks until he eventually is appointed boss.

Chris initially questions Tony's decision to contract the job out to their friends in Naples, but later decides it was a smart move.

Chris' readiness for the responsibility of leading his own crew is unclear as he is distracted by a potential career in Hollywood, relapses into drug use, and displays unresolved feelings over his murdered fiancée.

Chris' crew get involved in a credit card fraud scam; his AA sponsor James "Murmur" Zancone and Benny Fazio take numbers from local businesses and sell them on to associates Ahmed and Muhammad.

He has a belated bachelor party with the Soprano crime family at Nuovo Vesuvio, where "Larry Boy" Barese makes a toast to his future.

Throughout the episode's remainder, Tony displays the proper decorum for the family in mourning yet can barely restrain his relief that he is finally free of the burden Chris has placed upon him for so long – his insubordination, his substance abuse, his reckless behavior, and his complaints.

When Tony expresses confusion at the infant Chris' behavior around him, a woman at the table tells him that "some babies, when they come into the world, know all kinds of things from the other side."