Have you ever heard of Glen Rogers?

Probably not because Glen Rogers is one of America’s least-known serial killers (70, possibly 80 people). But wait. He is also most likely the real murderer of Nicole Brown Simpson and Ron Goldman.

ID’s feature-length documentary goes back over Rogers’ life and his crimes through interviews with police, prosecutors and with his family —most notably his former non-murderous partner-in-crime, brother Clay Rogers, who taught Glen how to steal at an early age.

Not only did Clay cooperate fully in this documentary, but he is the person who turned Glen in when he discovered a rotting corpse in the family’s broken down cabin in the woods in Hamilton, Minn.

The corpse was that of an elderly male neighbor, one of the very few men it turned out Glen had killed. At that moment, Clay realized that all those tall tales his brother had telling about killing 50 people were tragically true.

Since killing 50 people isn’t the kind of thing most people brag about, you’d have thought his brother would have figured it out, but he didn’t.

Then again, the whole family thought Glen was lying when the then-handsome lunatic told his family that he was “partying” with a woman in LA named Nicole Brown Simpson — just before she was murdered.

When Rogers phoned his family in 1994, according to the film, he actually said he was working and partying with her and that she was rich, and that he was “going to take her down.”

A few years after the murders, when Rogers was already on death row for other murders, he admitted to a criminal profiler that he’d killed Simpson and Goldman.

And there is at least some proof to back him up, including receipts that show Rogers had been working construction in the area at that exact time.

Rogers seemed to know things about the murder that only the killer could have known including a step-by-step description of the exact sequence of the killings which had eluded prosecutors and cops.

And OJ did in fact know the killer, the film says.

So why didn’t OJ bring all that out at the trial — or even before he was charged?

Because, according to Rogers, OJ had paid him to break into her house and steal a pair of $20,000 earrings the football star had given her.

Rogers claims OJ also told to kill “the bitch” if necessary.

After that murder (hardly his first), Rogers embarked on a cross-country killing spree.

So how does someone become such a psychopath?

Clay Rogers tries to explain it by talking about their horrific childhood with half a dozen siblings.

It was so awful in fact that chances were good that at least one of them would go from petty crime to murder at some point.

But 70 killings?

True or not. frightening, well done and riveting.