It may help in crime scene reconstruction (12)
I believe the answer is:
reminiscence
'it may help' is the definition.
The definition suggests a singular noun which matches the answer.
'in crime scene reconstruction' is the wordplay.
'reconstruction' indicates anagramming the letters (I've seen 'reconstructions' mean this).
'in'+'crime'+'scene'='incrimescene'
'incrimescene' with letters rearranged gives 'REMINISCENCE'.
Can you help me to learn more?
(Other definitions for reminiscence that I've seen before include "Recall of past times" , "Enjoyable recollection" , "It recalls happenings" , "Memoir" , "Memory" .)