Life has gotten harder and harder these days for would-be assassins. Some jurisdictions make it totally illegal to carry loaded guns in public, even if you really need to kill a guy.
"But you don't understand, officer. I was very angry at him!"
In the past, you could always depend on your trusty violin case, but with American orchestras going bankrupt left and right nowadays, people running around with violin cases are becoming a rarity and no longer blend into a crowd.
And old-fashioned high-tank toilets have been antiques for decades, so good luck taping a gun behind one of these modern toilets.
Seriously. Where would you even ...?