Resolve to imprison one for a type of murder (7)
I believe the answer is:
deicide
'a type of murder' is the definition.
(murder of a god)
'resolve to imprison one' is the wordplay.
'resolve' becomes 'decide' ('decide' can be a synonym of 'resolve').
'to imprison' indicates putting letters inside.
'one' becomes 'i' (Roman numeral).
'decide' enclosing 'i' is 'DEICIDE'.
'for' acts as a link.
(Other definitions for deicide that I've seen before include "Killer" , "The killing of a god" , "Killing of divine being" , "dispatch for Mars, say" , "Most unholy of sins" .)