"Why is there a crutch on our front porch?" I asked him.
He had no idea.
The logical answers are this:
1. There is (was?) a crutch in the garage. Maybe a neighbor kid broke in and stole it, got busted by his parents, returned it anonymously.
2. We are of course living in a new-to-us house. Maybe someone borrowed it from the previous owners and just returned it -- not knowing they moved.
But the first thing I thought, before I even considered the logical answers, is that the Crutch Serial Killer was leaving his calling card. That he stalks his prey for weeks, eventually leaving behind a crutch. Then he sneaks into the house, hides in the spare bedroom until the right moment, and then he skulks into the shower, and breaks your leg. That crutch on the front steps is like a punchline before the joke. The Crutch Serial Killer and his maniacal laugh: "Whaa Ha Ha. Now you know why I left behind the crutch."
And that is how I know I'm watching too much "Criminal Minds."