Caught red-handed means discovered in the very act of doing wrong. Caught red-handed at the till, caught red-handed with it, fairly caught red-handed.
There is no room for doubt in it, which is what separates it from being suspected. The red hands were once literally bloody, from an old Scottish law about being taken with the blood still on you.
1phrasecaught red-handedDiscovered in the very act of doing wrong.
“He was caught red-handed with the takings in his coat.”
caught red-handed is a phrase.
Also accepted in games: red-handed, red handed
Practised in Idioms