Benjamin, along with Oleg Mickic, were hired by George Novikov to kill Isaak Sirko. Isaak had "made both men rich" in the past, and called Oleg in an attempt to keep them from killing him, hoping that they had some loyalty to their former employer. However, Oleg told Isaak that they had already accepted the contract, and that they would be after him. At first, Isaak tries to get Dexter Morgan to help by saying he'll let him live, but, when that doesn't work, he has his bodyguard, Jurg Yeliashkevych, kidnap Hannah McKay, threatening to have her killed unless Dexter kills the hitmen. When Dexter agrees to help, Isaak informs him of both hitmen's method of killing. Oleg prefers to kill using firearms from far away, whereas Caffrey prefers to kill up close.
After Oleg is killed, Benjamin talks to George in the Foxhole, telling him that he can't get in contact with Mickic. George tells him to follow Dexter Morgan, thinking that he'll lead him to Isaak. Benjamin tracks Dexter to one of the Phantom Arsonist crime scenes at a local college and follows him from there. Along the way, Benjamin informs George that Dexter is leading him to a port where the Koshka Brotherhood has a freighter for transporting their drugs. Benjamin stealthily follows Dexter onto the freighter and takes out his knife. As he approaches, Dexter takes out his own knife, but before he gets to use it, Isaak calls out "Sweetheart!", causing both Dexter and Benjamin to turn around. Isaak then guns Benjamin down using a silenced pistol.
Afterwards, his body is dumped overboard into the ocean by both men, and Dexter cleans up his blood. Shortly after, George arrives and shoots Isaak fatally in the gut as he leaves the freighter, and, although it seemed George intended to kill Isaak with a gunshot to the head, he had to flee when he saw Dexter approaching.
- Isaak Sirko - Caffrey failed to kill Isaak as he was ultimately killed by the latter thanks to Dexter's help.
- Isaak states the preferred method of kill of both men, Oleg preferring long distance kills with firearms and Benjamin killing up close by any means. Ironically, Oleg is killed by being stabbed in the back, whereas Benjamin is shot from afar by Isaak.
- Caffrey could be considered similar to George King "The Skinner" in that Caffrey allows the members of the Koshka Brotherhood to select the victims for Caffrey to terminate, in the same way that King picked associates of Fred Bowman to make his targets, but Caffrey's preference of using knives and piano wire to kill his victims up close and personal imply a sadistic pleasure in the kill.