When It Happens

Paul and Louise have been homicide detective partners for ten years.  He is the analytic thinker and she is an ex-military, take-charge badass.  He figures who did the crime, she cuffs them.     Paul is shot in the back at his home.  Lou starts investigating to find the killer.  Paul returns as an apparition to help her.    Paul was doing an off the books investigation for the Governor.   The people he was investigating wanted him dead.    Lou needs help solving the crime.  Paul's spirit has no way to communicate or help her.     The Devil will give Paul's spirit the powers needed, if he can take a soul for the Devil.  Or, Paul can go to heaven if he saves a soul.  His desire to avenge his death is strong.
 His choices are clear, take a soul or save a soul.   The consequences will last for eternity.     He gets powers from the Devil and helps Lou with the investigation. He points her to a number of suspects, but she charges his best friend anyway.  A flamboyant attorney defends Paul's friend but the evidence is strong.  A surprise witness testifies and identifies the murderer.  Paul's friend is acquitted.  His soul is saved.
The real killer is a surprise to everyone. Paul pursues the killer with all the powers Satan gave him.  The killer runs, but can't hide.  Paul finally takes a soul for the Devil when he kills his murderer.       He saved a soul and took a soul. Will he remain in purgatory?  Where will Paul spend eternity?