Some TMNT stuff really isn't for little kids.
He first encountered the Turtles when they raided a meeting between the Phantoms and a gangster named Lupo, but retreated as Dun did not wish them to be seen openly yet. After being contacted by a Foot Assassin named Jennika, Jammer led the Street Phantoms in a failed assassination of Splinter, where he fought Alopex and Leonardo. Alopex destroyed two of the cloaks, and Leonardo managed to knock out Jammer and Maze, who were then carried away by their cohorts.
Later, he, Maze and Turk were lured into a trap by Nobody and Donatello, who were waiting for them with a device designed to neutralize the effect of the cloaks. Jammer responded with an EMP gun, and was forced to flee when the police arrived.
Later, the trio abducted Harold Lillja from his laboratory, and brought Libby Meitner to speak to him at Dun's behest. He was temporarily blinded by Harold during his escape, but quickly recovered and joined the other Phantoms in the search for Harold. He was then redirected to protect the building from the invading Foot Clan, which brought him into conflict with the Turtles. During the battle, Donatello defeated him and smashed his mask.
Along with the other Street Phantoms, he was brought to Darius Dun's office and witnessed Dun's execution on Splinter's orders. Afterwards, Splinter released Jammer and the other Phantoms.