Luther: Deniabilty. Look, if we get caught.. Alice: I say you forced me to help. That you threatened my life. Luther: You're not even joking, are you ? Alice(deadpanned): Absolutely not.
Episode six, when Luther is cleaning out the gun used to frame him. Alice rolls her eyes at the amateur job he is doing and simply plucks it out his hands and takes the gun apart and cleans it like an expert.