Understood to be arrested (11)
I believe the answer is:
apprehended
I believe this is a double definition.
'understood' is the first definition.
(apprehending is a kind of understanding)
'arrested' is the second definition.
('apprehend' can be a synonym of 'arrest')
'to be' acts as a link.
(Other definitions for apprehended that I've seen before include "Caught" , "Arrested - understood" .)