Green’s Dictionary of Slang

that part of southeastern Spain where many British criminals have chosen to live.

1986		F. Taylor Auf Wiedersehen Pet Two 36: Kenny can do sod-all with it while he’s stuck on the Costa del Crime.
1999		Indep. 17 July 12: Greene, 57, a Londoner, disappeared recently from the ‘Costa del Crime’ in Spain [...] as officers planned to arrest him in connection with a multi-million pound drug smuggling operation.
2000		J.J. Connolly Layer Cake 29: Nice fuckin tan cos he’s just got back from a little working holiday over on the Costa del Crime.
2005		N. Gaiman Anansi Boys 124: Otherwise he’d be off to the Costa del Crime before we could say ‘prima-facie evidence.’.