What character? It sounds like one of the older Doctors, almost, but for the thief thing.All from the same fictional character...
"Easy! Take it easy! I hate personal violence, especially when I'm the person."
"I steal things. compulsive, I'm afraid. I've had my head adjusted by some of the best in the business. But it just won't stay adjusted."
"A professional thief?"
"More a vocation than a profession; other people's property just comes naturally to me."
"Nervous? I'm not nervous. Just... poised for action, that's all."
"...That's immoral. The cold-hearted murdering -- let's kill him now before he can do it."
"Tell him I've just worked out a completely new strategy. It's called Running away."
"Hello there. How are you? Excuse me wandering about your premises but I wonder if you can help me. I'm an escaped prisoner. I was a thief but recently I've become interested in sabotage, in a small way you understand, nothing too ambitious, I hate vulgarity, don't you? Anyway, I've come to blow something up. What do you think will be most suitable?"
"Look, you don't have to give reasons. You don't even have to explain. Whatever it is, we'll back you up."