I'm sure no one would ever do murdering _twice_.

Think of the blood and things, and what you would see when you woke up in the night! I shouldn't mind being a detective to lie in wait for a gang of coiners, now, and spring upon them unawares, and secure them--single-handed, you know, or with only my faithful bloodhound.' She stroked Pincher's ears, but he had gone to sleep because he knew well enough that all the suet pudding was finished.

He is a very sensible dog.

'You always get hold of the wrong end of the stick,' Oswald said.

'You can't choose what crimes you'll be a detective about.
You just have to get a suspicious circumstance, and then you look for a clue and follow it up.