Detective goes after taking too many chances (4)
I believe the answer is:
odds
'chances' is the definition.
(thesaurus)
'detective goes after taking too many' is the wordplay.
'detective' becomes 'ds' (detective sergeant).
'goes after' means one lot of letters go next to another.
'taking too many' becomes 'od' (overdose).
'ds' after 'od' is 'ODDS'.
(Other definitions for odds that I've seen before include "The likelihood of something occurring rather than not" , "Betting likelihood" , "Perhaps even money" , "Chances, probability" , "prices" .)