However, this phrase is considered quite formal and not commonly used in everyday conversation.
A more natural and idiomatic way to say "caught red-handed" in French would be:
* "Pris en flagrant délit" (literally "caught in the act of crime") - This is the most common and versatile expression.
* "Pris sur le fait" (literally "caught on the fact") - This is similar to "pris en flagrant délit" and is also frequently used.
The choice between these two expressions depends on the context and the desired tone.