Slater is a CIA agent who initially poses as an arms dealer in Florida. He later become the CIA's liaison to ISIS once the agency is re-established by Malory Archer. Due to his actions, he can be considered one of the main antagonists of Season 6 of Archer
Slater appeared in On The Carpet as an arms dealer who deals in cocaine in exchange for weapons. Slater shot Archer with a bean bag gun, unaware who it was in the airplane that was delivering his cocaine. He then acted as if he knew Archer, by saying, "Classic Rando!" Rando was the disguise name that Archer picked when he introduced himself to Slater.
Slater re-appeared at the end of Filibuster with Agent Holly in San Marcos and it was revealed he's a CIA agent and part of a scheme to deplete the CIA's annual budget by selling Governor Gustavo Calderon's cocaine supply in exchange for weapons to fight his civil war. Slater was surprised when he saw Archer (Rando) until Holly informed him that Rando is actually Sterling Archer. Though he attempts to escape, he is held at gunpoint by a panicked Lana, who is in the middle of labor. He is detained up until the escape from San Marcos, assisting Ray in flying the plane back to the America.
After ISIS is re-established and contracted to the CIA in season 6, Slater acts as the agency's liaison and occasional ally, though he is openly unimpressed with their standards. The illegal acts Slater has done were:
-In Sitting, he pretended to have been shot by Pakistani Intelligence just so Lana could see if Archer was trustworthy if the baby. It is most likely that Slater decided to go in on this only because he wants to date Lana and he didn't know that the actor hired actually had a real gun on him.
-He was hiding Welsh terrorists from MI5.
-In The Kanes, he and several CIA agents stole research notes from Lana's father since they considered his work to be a threat to national security. Slater ended up bribing Lana's father to forget this whole thing ever happened once he realized that Lana and Archer were in the area. Lana was angry at Slater for shooting at them while her infant child was in the house.
-In Pocket Listing, he tries to steal the fingerprints from the prince of a royal family. Also, Slater kept bullying Kreiger by firing darts at them and kept wishing he brought poison ones with him.