|Portrayed by||Terry Kinney|
|Name||Samuel Bosco Jr.|
|Last appearance|| His Red Right Hand|
The Great Red Dragon (flashback)
|Profession|| CBI Senior Special Agent |
|Family||Mandy Bosco (wife)|
Similar to Lisbon in the CBI chain of command, Bosco, a married man, worked under Virgil Minelli, the administrator of the CBI, and led his own team of agents. Lisbon and Bosco shared a dark secret from the past involving a case they both worked on five years ago when Lisbon, a new agent under Bosco, was in the news heralded as a "saint". In the episode Black Gold and Red Blood, Lisbon threatened Bosco that she'd "talk" -- tell all -- if Bosco wouldn't comply with a demand, the implication being that there was a cover-up which, if known, would ruin both Bosco's and Lisbon's careers. Jane guessed at the end of the episode that Bosco killed a man, a bad guy, who he couldn't catch any other way, and that Lisbon found out after the fact and didn't tell anybody because the bad guy deserved it. Based on Lisbon's expressions and Jane's likelihood for being correct, it can be concluded that he was right.
When Jane told Lisbon that Bosco was in love with her, his comment surprised her. Jane's insight was proven correct later by Bosco's declaration to Lisbon on his deathbed.
Bosco and Jane had an antagonistic relationship based on lack of trust and the jealousy Bosco felt of Patrick. Jane didn't trust Bosco to properly investigate the Red John case, and Bosco viewed Jane as generally untrustworthy and unreliable: as a loose cannon rather than as a professional. As a result, Bosco was mostly immune to Jane's charms, though they started to like one another after being forced to cooperate.
In "His Red Right Hand", Bosco and his team were shot by his secretary Rebecca Anderson, who turned out to be an accomplice of Red John's. She was killed by Red John or one of his agents before she could reveal anything about him.
Bosco's team members were dead at the scene, but Bosco himself survived the attack for a couple of days before dying from his injuries. Before his death, he confessed to Lisbon that he loved her. He also reconciled with Jane, telling him that when he would catch Red John he should kill him rather than arrest him, and also asked him to protect Lisbon.