Short pause after each word, thank you :D
WHO:
A victim
A detective
A witness
An accomplice
A suspect
A culprit
To commit a crime
To help commit a crime
To investigate a case
To be killed to harmed
To be suspicious of a crime
To see or have important information
WHAT:
An alibi
Blood
A fingerprint
An evidence
A proof
A clue
A corpse
A knife
A pistol
A gun
WHY
A motive
A conspiracy
A treason
A revenge
A murder
Jealousy
Money
I hope that this helped you! ;)