"I've thought of it," I said. "Don't think I haven't."
"Where do I find one?" I said.
"You've found one," he said.
"You're crazy," I said.
"That's right," he said. "I've been in and out of mental institutions all my life. That makes my services all the more appealing. If I were ever to testify against you, your lawyer would have no trouble establishing that I was a well-known nut, and a convicted felon besides."
"What was the felony?" I said.
"A little thing -- practicing medicine without a license," he said.
"Not murder then?" I said.
"No," he said, "but that doesn't mean I haven't murdered. As a matter of fact, I murdered almost everyone who had anything to do with convicting me of practicing medicine without a license." He looked at the ceiling, did some mental arithmetic. "Twenty-two, twenty-three people -- maybe more," he said. "Maybe more. I've killed them over a period of years, and I haven't read the papers every single day."
"You black out when you kill, do you," I said, "and wake up the next morning, and read that you've struck again?"
"No, no, no, no, no," he said. "No, no, no, no, no. I killed many of those people while I was cozily tucked away in prison. You see," he said, "I use the cat-over-the-wall technique, a technique I recommend to you."
"This is a new technique?" I said.
"I like to think that it is," he said. He shook his head. "But it's so obvious, I can't believe that I was the first to think of it. After all, murdering's an old, old trade."
"You use a cat?" I said.
"Only as an analogy," he said. "You see," he said, "a very interesting legal question is raised when a man, for one reason or another, throws a cat over a wall. If the cat lands on a person, claws his eyes out, is the cat thrower responsible?"
"Certainly," I said.
"Good," he said. "Now then -- if the cat lands on nobody, but claws someone 10 minutes after being thrown, is the cat thrower responsible?"