More than a decade after Sonny Liston’s 1970 death from what a coroner called natural causes—and police suspected was an accidental OD of heroin—bookies, mobsters and cops in Vegas still whispered about whether the former heavyweight champ had died at the hands of someone else. In this excerpt from his upcoming book, The Murder of Sonny Liston, ESPN senior writer Shaun Assael recounts the day in 1982 when a sergeant in the Las Vegas police force got a strange tip that set in motion a new round of questions.

From his gang unit office on the seventh floor of police headquarters, Gary Beckwith could look out over the two dozen officers under his command. One of the unintended consequences of the corporatization of Las Vegas was that it had chased out the old-time mobsters and allowed in a more murderous generation. A pathological killer, Tony Spilotro, made the ’70s the bloodiest decade on record when he was dispatched by the Chicago outfit to keep an eye on its Vegas interests, and he quickly threatened to kill anyone who didn’t pay him protection money.

But the mob wasn’t Beckwith’s biggest concern anymore. The Hells Angels were selling meth to schoolkids, and the black gangs who sold dope on the Westside had struck an unholy alliance with Mexican dealers who were taking over the desert line. As far as Beckwith was concerned, it was all a symptom of an even larger cancer: Las Vegas was growing too damn fast for its own good. Every time he passed a new construction site, he wondered how much more his city could stand.

With all of that on his mind, he wasn’t prepared to get a call at home after midnight from his boss, asking him to come back into the office. “Gary, I got a guy I need you to talk with,” the head of intelligence said.

“Can’t it wait?” Beckwith asked.

“I don’t think so. He says he’s got information about something about to go down.” The head of intelligence paused. “There might even be something in this that’s new on Sonny Liston.”

After Sonny Liston died

Beckwith had been one of the first officers to arrive at 2058 Ottawa Drive when Sonny’s wife Geraldine reported his death. Back then he was an undercover deputy who kept his hair in a ponytail and dressed in sleeveless biker vests. When one of his colleagues claimed to have found a bindle of heroin in the Listons’ kitchen, Beckwith was the one who was assigned to write the search warrant application and ask for permission to look for “any and all illegal narcotics, namely heroin.” The subsequent search hadn’t turned up anything. But Beckwith suspected that was because someone had gotten to the drugs before he could.

“Who is it?” Beckwith asked his boss on the phone.

“You ready for this?” his lieutenant asked. “It’s Gandy. He says he wants to give us Larry Gandy.”

It took a moment for the name to sink in. There weren’t many cops Beckwith admired. But in the 1960s and early 1970s, Larry Gandy was one of them. Lean, with a pompadour of jet-black hair and blue eyes that could freeze a 100-degree day, Gandy didn’t just take on the toughest assignments. He single-handedly declared war on the Westside.

What Beckwith remembered more than anything was the gimmick Gandy used, because more than a decade later it still inspired awe. In their days on the street, heroin was sold in clear gelcaps, usually $120 for a bag of six. Since most dealers wanted their customers to shoot up in front of them to prove they weren’t cops, Gandy bought his own capsules and filled them with maple syrup, tucking the placebo pills between his fingers before he went off to an undercover buy. Once he’d bought real heroin, he’d switch the capsules he bought for the fake ones and shoot maple syrup into his vein. It was so utterly bizarre that no one who witnessed him tying off could imagine it was a con.

The junkies all got dragged into headquarters in handcuffs thinking each had set the other up. In an era when every other cop was either on the take or out of his mind, Gandy was clear-eyed and incorruptible.

But then, suddenly, he wasn’t.

All the cops from Beckwith’s generation knew the story. In the mid-’70s Gandy had trouble adapting to the newer, more by-the-book era of policing. There were sensitivity classes and lectures about engaging suspects with conversation instead of fists. There were also managers with advanced degrees who’d never spent a day on the street and instead sat in their offices looking at statistics. For Gandy it was heartbreaking to watch cops worry about covering ass instead of kicking it. He was a man lost in another era. And, invariably, it caught up with him.

Beckwith wasn’t 100 percent clear on the details. Something about someone threatening Gandy’s female partner. Whatever it was, Gandy beat the crap out of the guy and got sued for police brutality. His supervisor demanded that he take a lie detector test and the two got into one of those “F— you,” “No, f— you” fights. He was fired for insubordination and responded by suing the state in a case that added to his legend. Not only did he win his job back, he won a precedent that gave police officers the same rights as suspects in refusing to take polygraphs. After that, he said “F— you” one last time and walked away for good.

As far as Beckwith and every policeman in that building were concerned, Gandy was still a hero.

By June of 1982, most people had settled on the simplest explanation for Sonny’s death, which was that he overdosed himself on a heroin bender while Geraldine was away. Certainly that was what Beckwith thought when he drove back to his office past midnight and readied himself for what the man who wanted to spill all about Liston, Irwin Peters, had to tell him.

Peters was already in the middle of telling his story to two detectives when Beckwith arrived at the small interview room. Peters was tall and wiry, with red hair that stood on end as if it were magnetized by negative energy. Beckwith nodded to the men to keep talking and pulled up a chair.

Peters was telling the detectives about his background in crime, which started in Mexico when he supported his young family by selling bogus securities to unsuspecting tourists. U.S. authorities collared him, and in exchange for ratting out his friends he got one-way bus tickets to Vegas for his family.

Once they reached town, Peters took a job at an AAMCO transmission shop on West Bonanza that was a way station for small-time hoods who dealt drugs and looked for scams. Inevitably, Peters wound up running his own cons that got him in enough trouble to land him in the Las Vegas jail.

There he caught the eye of a sergeant who turned him into an informant—and assigned him to Larry Gandy. And as they said in the movies, it was the beginning of a beautiful friendship. Despite his red hair, Peters managed to be forgettable enough to rarely make an impression, which made him a great snitch. He’d hear all sorts of things that he passed along to Gandy, some of which helped him win cases and some of which he traded on the street. In return, Gandy was good to Peters. He used an informant budget to give Peters money for tips and kept him on the payroll long after he should have been locked up.

For the better part of eight years things worked well. And when Gandy quit the police department, Peters assumed they’d go their separate ways. But that turned out not to be the case. Gandy’s legal fight against the brutality charges lodged against him were expensive; he’d nearly bankrupted himself fighting them. To dig his way out, Peters said, Gandy flipped the script and did what he knew best: He went back to the streets, this time as a crook, not a cop. In a one-man crime wave, he started ripping off the very same drug dealers whom he used to arrest, by stealing their drugs. Once he got a haul, he’d resell it to the executives he knew in the casinos, the ones who made it their business to supply the high rollers. It was a perfect setup, Peters said. Who was going to complain? Nobody.

But drugs were just the beginning. Gandy also had a real estate appraiser’s license and used his access to houses to case them for burglaries. When Gandy settled on a target, he’d call Peters with instructions to go in first. “I’d go in with a shotgun,” Peters said coolly, showing no hint of remorse. “I’d tell them I’d blow their heads off if they didn’t get on the ground.” After they were subdued, he said, he’d pull pillowcases over their heads and give Gandy the all-clear sign. Then his partner would come in and loot the place. Gandy also had a trademark, Peters said. He masked his voice by talking like Daffy Duck.

Beckwith studied Peters, trying to figure out his angle. It was clear that Peters was angry with Gandy. Over and over he said that Gandy had cheated him out of a share of their heists. Beckwith found that part reassuring: He always preferred to know someone’s motive. But Peters irked the sergeant when he said, “And remember that Sonny Liston thing? Gandy killed him. He shot Sonny up with heroin.”

“That’s where you lose me, Pete,” Beckwith said, making no effort to mask his irritation. “There was no murder. It was natural causes.”

Peters waved off the decade-old coroner’s finding. “That wasn’t an overdose,” he said. “It was murder. Gandy bragged about it to me after he did it.”

Beckwith replayed the early-morning hours of Jan. 5, 1971, in his mind. Now that Peters mentioned it, he did remember seeing Gandy in the Listons’ home. He’d recognized the undercover cop from an incident months before, when they had both been lured to the same house by an informant and nearly got into a shootout. At Sonny’s house they’d nodded hello, but that was about it.

After grabbing a few hours of shut-eye at home, Beckwith returned to the office to dig into Peters’ story. He assumed he’d find it full of holes. But, to his surprise, when he compared the addresses of the houses that Peters said they’d robbed with open cases in the department’s files, he noticed that many of them matched. As he read through the reports, he also noticed one striking similarity: Many victims reported that while they were blindfolded they heard the voice of someone who sounded like Daffy Duck.

The more Beckwith read, the more he realized Peters wasn’t as easily dismissed as he’d hoped.

Decades later, it wasn’t hard for me to track Larry Gandy down.

I used Facebook.

To judge from the photos he’d posted, he certainly didn’t look like someone you wanted mad at you. He was about 50 pounds heavier than his police days, and his photos showed him in sleeveless biker vests highlighting biceps that looked like they belonged in a Toby Keith video.

He wore a trim goatee that matched his military buzz cut, and even in happy-looking scenes there was very little reassuring about his smile. Still, given what his friends said, it seemed that there was something that wasn’t quite coming through in those photos. So I sent him a message: “Since so many years have passed, I’m hoping you’d be open to sitting down with me to talk about your life and career.”

Within a few hours, I received this reply:

“I would be delighted to sit down with you. As you know, I was well known in the old days. Some of my activities were positive and some were shameful; however, I have come to terms with my life and realize that I was responsible for my actions. … There was a time I would have recoiled at your request but, like I said, I have come to terms with my past.”

In a follow-up email, he went on:

“I promise you I will be candid and honest with you. I have come to realize over the years that you’re remembered for the bad things you have done, not the good. … I can’t justify any of my behavior but can only give you the facts. I know the difference between right and wrong. It should be noted that I have finally forgiven myself and have quit carrying that bag of rocks up the mountain looking for a penance. See you!”

We agreed to meet on one of those post-Christmas days in Las Vegas where you can make a few green lights on the Strip and get out of town fast. I drove past the shopping centers pushing this city ever farther into the desert and toward the towering cliffs of Red Rock Canyon, until I pulled into an airy development. Checking the batteries in my tape recorder, I walked to the address Gandy gave me.

Before I could ring the bell, the door flew open to reveal a man who looked like Santa Claus in the offseason: roundish and gray-haired with a jolly smile and biker tattoos all over his body. When he held out his hand, he brimmed with genuine enthusiasm.

I’d prepared dozens of questions, but he didn’t let me get to any of them. Instead, Larry Gandy wrapped his thick arm around me and said, “So, you’ve come to ask me if I killed Sonny Liston.”

This story appears in ESPN The Magazine’s October 17 Great Debates Issue.

Liner Notes Excerpted from The Murder of Sonny Liston, out Oct. 18, by Shaun Assael. Copyright © 2016 by Shaun Assael. Published by arrangement with Blue Rider Press, a member of Penguin Random House.