|Minor Character: Miami|
|Portrayed By||Tom Hillmann|
|First Appearance||Double Cap|
Dennis Sackheim (referred to mostly as Special Agent Sackheim) is an FBI Agent who appeared in two episodes of CSI: Miami, plus the crossover episode of CSI: Crime Scene Investigation titled Cross Jurisdictions.
Sackheim is shown as rash and unrelenting, often conflicting with the interests of the MDPD (especially Horatio, with whom he interacts with the most). The investigations of his bureau intertwined with those of the MDPD on 3 occasions as shown in the 3 episodes he appeared in.
Sackheim is introduced in the crossover episode Cross Jurisdictions, where he and the FBI were targeting Gordon Daimler impetuously.
In Double Cap, Sackheim once again appears, where his botched operation to capture the prime suspect concerns Lt. Horatio Caine as it may have allowed the killer to walk free.
The episode Wannabe is Sackheim's final appearance. One of the FBI's undercover agents, Avi Golan from Israel, is murdered by Danny Fisch, and he happened to be the closest to bringing Fisch down. Sackheim loses patience upon discovering that evidence was compromised at the crime scene, and threatens to take down the MDPD if his division in the FBI is terminated for Fisch walking free. Fisch's blood is eventually found on the crime scene and he is walked out of the department building in handcuffs, escorted by Sackheim, who has a pleased look on his face.