The Illustrated Guide to Criminal Law
Chapter 9: At Least You Tried
Attempt pg 23: Limitations of Impossibility
But Frick and Frack, on the other hand, do not have that defense.
Frick planted a bomb in your mailbox (what is it with you, anyway?). The bomb’s fuse was defective, however, so it couldn’t go boom.
Older man placing a cartoon-style bomb in a mailbox
He’s trying to commit the crime, but it’s impossible. Unlike Joe, however, he could have succeeded but for circumstances beyond his control (or of which he was unaware). Frick is still dangerous, and so he’s still guilty.
And if he chose a defective bomb on purpose, in order to scare you? Isn’t he guilty of a lesser crime in that case?
That’s not what we’re talking about here, though. The issue is whether he can claim the defense of impossibility. In your scenario, he’d simply be trying to commit a different crime.