Stevie D

Stevie D, or Steven Douglas, is a professional assassin. He first appears in Changes.

Description
Stevie D is a blocky professional assassin who killed Torelli a few years prior to the events in Changes. Harry Dresden had heard of him before.

He seems to genuinely care whether Waldo Butters survived being shot by him. He asks how the little guy is and he is relieved to learn that Butters was wearing a Kevlar vest. He says he wouldn't want to do time for killing the wrong guy, but that everything he had heard about Harry told him that he couldn't play around, and he had needed Butters out of his line-of-sight.

Changes
In Changes, Stevie D shows up at Saint Mary of the Angels, where Harry Dresden, his back broken, has gone seeking shelter from the Eebs who can't enter the sanctuary. Stevie D shoots Waldo Butters twice to get him out of the way, then aims at Harry's head. Harry utilizes his new ability access ice in a spell that freezes the gun. Stevie drops it. Father Forthill tackles the assassin, who kicks him in the jaw. Molly tries to fight him, but Stevie elbows her in the neck. Butters then zaps Stevie with the naked wires of the defib unit, making him lose consciousness. After Stevie comes to, Harry questions him. After Harry threatens to inform John Marcone on him, he reveals that a woman matching Susan Rodriguez's description hired him to kill Harry. As agreed, Harry releases Stevie D.

Harry deduces that it was the Eebs, not Susan, who hired Stevie D to kill him inside Saint Mary's. Esmeralda Batiste can make Stevie believe she was Susan with her eyes. And it's exactly her style.