> someone was arrested "after" a drug bust

Bingo! this just seen on the the Beeb's Red Button: someone being "detained", then "arrested". I'll check, but to be formally arrested, methinks there needs to be one or more specific charges, and the defendant must then go before the Beak. One can instead (or first) be detained, which (like being chucked in the cooler after an excessively good celebration) need not necessarily lead to a charge.