Why did the young cop decided to kill Harvey?
Who the hell was he anyway? Was he an inmate or did he work there?
First he was in the cell and then he was helping out.
I thought that when the blood touched you that you only saw scenes from the murders that Helen commited.
Remember when the young cop was taking fingerprints and he was touched by the blood and suddenly had all those "flashbacks" of a man murdering and raping women? That was Harvey, hence why he shot him.
As for your last statement, there seems to be differing opinions, maybe it was a flaw in the script, or perhaps it was that all those murders occurred in the same 150 mile radius (as one of the cops mentions) so it's possible that it's not just Helen's victims, but ALL the victims buried in that area that came together to form Bloody Boy.
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