If you were riveted by the finale of Apple TV Plus miniseries Black Bird and immediately Googled whether or not it's a true story -- you've come to the right place.

Jimmy Keene, who was arrested for dealing drugs and sentenced to 10 years behind bars, was indeed offered freedom in exchange for coaxing a confession out of suspected serial killer Larry Hall. You can find the full details in Keene's book (co-written with Hillel Levin) or in this transcript of CNN's report. Below, you'll find the key details that actually happened, including accounts and quotes that come up in the show.

Who was the real Jimmy Keene?

A charismatic golden boy who grew up as a popular athlete in high school? The real James Keene fits the description.

Keene grew up in Kankakee, Illinois, raised by his father, local police officer "Big Jim." Keene had his own nickname on the football field -- "the assassin," for putting players out every game. "Everybody knew who I was with my sports ability," Keene told CNN. "I was voted the most popular guy in school."

What crime did Jimmy Keene commit?

Despite his popularity, there was one thing Keene didn't have in spades: money. To keep up with his rich classmates, Keene started selling drugs. By the time he was 20, he was reportedly taking in $1 million per year. Not only able to support his financially ruined father, he was more popular than ever, hosting huge parties and living in a mansion. "It's hard to walk away from that kind of money, especially a 20-year-old," Keene said.

But in 1996 the DEA and FBI came knocking. "I heard the front door rattle, and I thought it was just the wind," Keene said. "It was November. And next thing you know, boom, the whole door just blew off the hinges. And then they came flying in a straight file line with their guns drawn and their black uniforms. 'Move, we will blow your head off. We will do this. Just move one time, blah, blah, blah.'"

After reportedly refusing to give up other drug dealers, Keene was sentenced to 10 years.

Who was the real Larry Hall?

Larry Dewayne Hall was born in 1962 in Wabash, Indiana. He really did have an identical twin brother named Gary, the more "dominant, outgoing twin," Gary told CNN. On the flip side, Larry Hall said in an interview obtained by CNN, "I know, when I was born, my mother told me that I was blue, that I hadn't got enough oxygen to me or something."

The brothers grew up next to a cemetery, where their father worked. Aged 12, Gary and Larry started working there too. Best friends, the brothers became Civil War reenactors as a hobby, leading to Larry growing muttonchops.

What crime did Larry Hall commit?

In 1994, Larry Hall was convicted of kidnapping 15-year-old Jessica Roach, who was last seen in 1993, riding her new bicycle near her home in rural Georgetown, Illinois. She was found dead six weeks later.

Hall confessed to murdering Roach, Tricia Reitler and two other women in a police interview, but recanted his statement, claiming to investigator Gary Miller (named Brian Miller and played by Greg Kinnear in the show) he was just referring to his dreams.

Still, federal prosecutor Larry Beaumont had Hall convicted of kidnapping Jessica Roach. "In the federal system, if you're guilty of a kidnapping and that kidnapping resulted in a death, then under the sentencing guidelines it's a mandatory life term," Beaumont said.

Did Jimmy Keene really try to befriend Larry Hall?

While Jessica Roach's case was closed, the disappearance of 19-year-old Tricia Reitler remained unsolved. To give her parents some semblance of peace, prosecutor Beaumont hatched a plan.

In 1998, 10 months into his sentence, Jimmy Keene received a visit from Beaumont, the very prosecutor who had sent Keene to prison. Beaumont presented Keene with a shocking offer: transfer to a maximum-security prison, befriend alleged serial killer Larry Hall and learn where Tricia Reitler was buried. In return?

"If you can get solid confessions from him, and if you can help us locate the bodies that are still missing, we're willing to completely wash your record," Beaumont said, according to Keene.

It was a life-risking operation and Keene hesitated to accept. But then his stepmother informed him his father had suffered a stroke. Still, on the drive to the prison in Missouri, Keene got cold feet. "I looked at the US marshal, and I said, 'Listen.' I said, 'How do we know Beaumont's going to live up to his word?' They all assured me he would. I said, 'I'm not sure if I can do this.'"

But there was no going back.

Was Keene successful?

Keene did  manage to befriend Hall. His descriptions of his exchanges with Hall are fascinating.

"I made it a point for us to bump shoulders together, and as we gently bumped shoulders together I turned around and said, 'Excuse me.' I said, 'Listen' -- I said, 'I'm new here' and said, 'You wouldn't happen to know where the library is, would you?'"

"And I just reached over and I kind of slapped him on the shoulder and I said, 'Thanks a lot. I appreciate that from a cool guy like you.'"

Keene watched Hall diligently from his cell across the hall.

And I walked up to him and I says, "Hey, this is where I'm at." I said, "Are you in this area here."

And he says, "Yes, I'm right there." And he bugs his eyes out of his head.

I said, "Well, that's great." I said, "You're right by me." I said, "You know what? I told you you were a cool guy, and I'm glad that you're by me" and all this and that. And that's when he basically offered sometime if I'd ever want to have breakfast with him and his friends.

Keene beat up a "real big buff guy" for changing the TV channel from a show Hall was watching. Trusting Keene, Hall told him the truth about what happened to Tricia Reitler, admitting that he choked her to death and buried her in the woods.

Still needing the exact location, Keene thought he'd scored the jackpot when he found Hall with a map covered in red dots over Indiana, Illinois and Wisconsin. At the edges of the map, stood a line of a dozen wooden falcons. "They watch over the dead," Hall said, according to Keene.

Believing he had everything to gain his freedom, Keene unleashed his true opinion of Hall in a barrage of insults. Hall responded by saying, "Beaumont sent you, didn't he? Beaumont sent you, didn't he?" according to Keene. As well as blowing his cover, Keene was sent to solitary confinement for the outburst. The map and the falcons disappeared.

Despite gathering details on Tricia Reitler's murder and several others, Keene failed to find the location of her body. Luckily, Beaumont decided to see Keene receive credit for time served. "I made arrangements to have him take a polygraph test just to verify what he was telling us was the truth, which he passed. And he did make a legitimate effort to do what we sent him down there to do," Beaumont said.

Where is everyone now?

After becoming a free man, Keene was able to spend five more years with his father, Big Jim, before he passed away.

Hall continues to serve a life term in prison, but has never been charged with crimes against anyone other than Jessica Roach.

After Keene's book In with the Devil was published in 2010, the refocused attention on Hall saw cold cases reopened, putting pressure on Gary Hall, Larry's brother, to stop defending him.

"I went with the Indianapolis detectives down to try to get my brother to confess," Gary said.

Larry Hall confessed to 15 serial murders, but later retracted again. Hall is now suspected of having as many as 40 victims. Tricia Reitler's family is still waiting for answers.