Arrest witnesses reported (5)
I believe the answer is:
seize
'arrest' is the definition.
(thesaurus)
'witnesses reported' is the wordplay.
'witnesses' becomes 'sees' ('see' can be a synonym of 'witness').
'reported' indicates a 'sounds like' (homophone) clue.
'sees' sounds like 'SEIZE'.
(Other definitions for seize that I've seen before include "appropriate" , "Grasp hold of" , "Take hold of, grab" , "Take possession" , "Suddenly take hold of" .)