catch someone red-handed
US /kætʃ ˈsʌm.wʌn ˌredˈhæn.dɪd/
UK /kætʃ ˈsʌm.wʌn ˌredˈhæn.dɪd/

1.
cogliere in flagrante, prendere con le mani nel sacco
to discover someone in the act of doing something wrong or illegal
:
•
The police caught the thief red-handed as he was trying to break into the car.
La polizia ha colto il ladro in flagrante mentre cercava di entrare nell'auto.
•
My mom caught me red-handed eating cookies before dinner.
Mia madre mi ha colto in flagrante mentre mangiavo biscotti prima di cena.