Arrested but remained reserved (6)

I believe the answer is:

booked

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'reserved' is the definition.
(booking is a kind of reserving)

I cannot understand how the rest of the clue works.

(Other definitions for booked that I've seen before include "Reserved in literary way?" , "Reserved, arranged say seat in advance" , "Reserved, bought ticket in advance" .)

I've seen this clue in The Globe and Mail.

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