I have heard the following sentence in the TV series Marseille (S01E06@2:45) :
- Les keufs à mort! Cassez-vous!
Context: Some members of a gang in a violent neighborhood are talking. Suddenly, two guys appear in a moto, yelling the sentence above and shooting upwards. The intention is to warn everybody that the police are coming.
I know that "keuf" means "cop", but what does "à mort" mean in this context? I have seen in Wiktionary that it can mean "very" in some contexts, but that does not make sense here.