Busy magazine (7,3)
I believe the answer is:
private eye
I believe this clue is a double definition.
'busy' is the first definition.
(busy can mean a police officer or detective)
'magazine' is the second definition.
(I've seen this before)
(Other definitions for private eye that I've seen before include "investigator" , "Satirical magazine - undercover detective" , "Investigative satirical magazine" , "Periodical" , "50 today" .)