Crime heads manipulated old scientist (10)
I believe the answer is:
archimedes
'old scientist' is the definition.
(I've seen this before)
'crime heads manipulated' is the wordplay.
'manipulated' is an anagram indicator.
'crime'+'heads'='crimeheads'
'crimeheads' with letters rearranged gives 'ARCHIMEDES'.
(Other definitions for archimedes that I've seen before include "Old mathematician" , "Ancient Greek scientist (of buoyancy principle)" , "'Eureka' scientist" , "Greek mathematician and inventor" , "Syracusan" .)