Frankie and Tony were killers.

No telling how many they killed.

But before they became dangerous hoodlums, Frank Cullotta and Anthony Spilotro were kids, growing up along Grand Avenue and getting into trouble.

Stealing, fighting, shooting dice and muscling other kids for their money at Riis Park in the 1950s.

Juvenile delinquents, we might have called them in my day. At-risk youth, maybe the current terminology.

Cullotta, 78, talks about this period and more in his new book, “The Rise and Fall of a ‘Casino’ Mobster: The Tony Spilotro Story Through a Hitman’s Eyes.”

Joe Pesci in the movie “Casino.”

Spilotro is an enduring character in mob history, the Chicago Outfit’s loose cannon in Las Vegas during the 1970s, made more famous by Joe Pesci’s character in the movie “Casino.”

Cullotta was his self-described “underboss,” a childhood friend who became his trusted henchmen in a wide range of criminal activity. Then a falling out led to Cullotta flipping on Spilotro and going into witness protection — as an alternative to Spilotro having him killed.

“Nobody alive and free today knows more about Tony’s criminal career than I do,” Cullotta boasts in “Rise and Fall,” the third book he and co-author Dennis Griffin have mined from a criminal career that ended in 1982.

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I’ll leave it to the mobologists to judge whether Cullotta breaks new ground about which murders he says Spilotro did and did not commit. (Corrupt ex-cop Richard Cain? Yes. Marilyn Monroe? No.) Cullotta promises new information.

But I was more intrigued to learn about Cullotta and Spilotro in their formative years in Chicago as the die was cast.

Frank Cullotta. | Supplied photo

Both were born in 1938. Cullotta says they were 12 or 13 when they met, an oft-recounted story of Spilotro getting in Cullotta’s face over which one was entitled to shine shoes on a stretch of Grand Avenue.

All was forgotten when Spilotro learned Cullotta’s gangster father had once helped his own father, the owner of Patsy’s restaurant at Grand and Ogden, deal with extortionists from the Black Hand. According to Cullotta, his father had them killed. End of problem.

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Cullotta said he quickly learned he and Spilotro had more in common than their age and being short.

“We both hated school and would fight at the drop of a hat,” he wrote.

Early on, Spilotro invited Cullotta over to his house, where Spilotro and his five brothers shared one bedroom with three sets of bunk beds.

Spilotro’s mother came in and asked who he was. Cullotta said he got the impression she wasn’t very happy about him being there.

“She said to Tony, ‘Hurry up and get out of here, the both of you,’ ” Cullotta said.

I can just picture that.

Spilotro’s parents were “hard-working, nice people,” Cullotta wrote. “I never knew either of them to be involved in anything illegal.”

In a phone interview Friday, Cullotta was insistent on that point, which I found curious because several of Spilotro’s brothers also went astray.

“They were good Italian people,” Cullotta told me. “Parents, they can only do so much. It’s who you hang with that determines the route you’re going to take in life.”

It was much the same with his own mother, who was left to raise him after his father died in a crash during a police chase.

Cullotta, who was just 8 at the time, fed on stories from relatives and his parent’s friends about his father’s exploits.

“I wanted to be like him, and nobody was going to stop me,” Cullotta said. “My life was set in motion right after his death. My mother tried everything she could.”

Cullotta said it was Spilotro’s older brother Vic who was his bad influence. Vic was a bookie and street hustler who dressed well, drove a nice car and aspired to being a real gangster. Spilotro looked up to him.

To learn how the system tried — and failed — to straighten out Frankie and Tony, check back on Tuesday.