Richard Green, 46, suicide by handgun on July 1, 1983.

Mitch Halpern, 33, suicide by handgun on Aug. 20, 2000.

Toby Gibson, 61, suicide by carbon-monoxide poisoning on Nov. 25, 2008.

Three Nevada referees. Three deaths by their own hand.

In the aftermath of still another referee’s irreversible decision to give up on life, questions abound. Why and how did these men, so respected within the boxing community, come to feel such overwhelming personal despair? Is there any correlation, any pattern, that links them beyond their profession? Or is this just another instance of cruel coincidence?

“I 100 percent believe that there was nothing boxing-related that contributed to the deaths of Mitch Halpern and Toby Gibson,” someone who knew both men, but asked not to be identified, told me. “Their only common denominator was that they were referees. But whatever was bothering them, and something obviously was, had nothing to do with boxing. I’m absolutely convinced of that.”

Gibson, who worked two undercard bouts of Saturday night’s card at the MGM Grand headlined by the junior welterweight clash between Ricky Hatton and Paulie Malignaggi, did not give any outward indication he was troubled when he worked the final fights of his 23-year refereeing career.

“He seemed normal, and everything was fine when I saw him on Saturday,” said Keith Kizer, executive director of the Nevada State Athletic Commission.

But something must not have been fine with Gibson because, two days later, he went into his closed garage, started the engine of his car and remained in the driver’s seat until there was no more oxygen left to breathe. His body was found by his wife, Barbara.

Was Gibson experiencing marital or family problems? Had the economic downturn dealt his stock portfolio or 401k account a knockout blow? Was he keeping secret any depression he might have been feeling?

My source said Gibson recently had lost his regular job, but he was uncertain if that could have spurred him to take his own life.

“He’d been learning mixed martial arts,” the source said, indicating Gibson was preparing himself to branch out into refereeing work in another combat sport. “I know he had lost his job with the State of Nevada penal system. He was taking some inmates up into the mountains where they were doing some forestry work. But whether that was a factor in this, I couldn’t say.”

Gibson, a native of Youngstown, Ohio, had served as the third man in the ring for boxing events in Nevada since 1985. He was generally considered to be a competent referee, if not necessarily an elite one.

Higher on the pecking order for major assignments were Green and Halpern, both of whom were regarded as among the best in the business.

Halpern got his start as a referee in March 1991 and he went on to work 87 world championship fights and hundreds of non-title bouts around the world. Among the signature events he worked were Evander Holyfield’s 11th-round stoppage of Mike Tyson on Nov. 9, 1996, the welterweight championship unification fight between Oscar De La Hoya and Felix Frinidad on Aug. 18, 1999, and the second fight between Lennox Lewis and Holyfield on Nov. 13, 1999.

Controversial endings are endemic in boxing, and any referee who works long enough or often enough can find himself in the harsh glare of public scrutiny. Although Halpern was rated as the second-best referee in all of boxing by The Ring magazine just months before he pointed a gun at his head and squeezed the trigger, he had been widely criticized for his work in the March 3, 2000, fight between WBA super welterweight champion David Reid and veteran power-puncher Felix Trinidad.

Although an Olympic gold medalist at the 1996 Atlanta Olympics, Reid was, despite his championship belt, something of neophyte professional with only 14 bouts when he entered the ring against Trinidad. By the time Reid made it to the final bell, he had been knocked down four times, thrice in the 11th round, and was clearly in distress. Reid was never the same fighter after that, and, fairly or unfairly, Halpern was criticized for allowing him to absorb more punishment than was necessary in a matchup the Philadelphian did not appear to have any chance of winning from the middle rounds on.

Could Halpern have been driven to the brink by a sense of guilt that he had not done all he could to protect the valiant but stricken Reid? Not likely; Reid kept attempting to fight back whenever he found himself in trouble, and referees, for the most part, are made of hard bark that is resistant to boos and putdowns.

“Was there ever anybody more vilified than Richard Steele?” my source said of another Nevada referee who found himself embroiled in more than a few disputed conclusions to high-profile fights. Steele, however, took the occasional slings and arrows and was adamant that he always had done his duty as he saw the light to do that duty.

More likely, it was personal issues that bedeviled Halpern, who was involved in a a child-custody case at the time of his self-inflicted death. Those who knew Halpern, who did not leave a suicide note, believe that “woman problems” were at the core of his despondency.

But the referee who most likely was consumed by grief stemming from his work in the ring was Green, who drew the assignment for the Nov. 13, 1982, bout at Caesars Palace between WBA lightweight champion Ray “Boom Boom” Mancini and South Korean challenger Duk Koo Kim.

Green, a Louisiana native who had been a Golden Gloves boxer in the 1960s, had earned generally high marks for his work in a number of big-time fights, including the Oct. 2, 1980 pairing of Larry Holmes and Muhammad Ali. Serving as the third man in the ring for Mancini-Kim, though, haunted him as much as it did Mancini, whose 14th-round stoppage in a bloody, two-way battle has weighed upon him like an anvil.

Kim slipped into a coma and died four days after the fight. His mother flew from South Korea to Las Vegas to be with her son before the fight and was the one who tearfully consented to having the life-support equipment turned off. Three months later, she took her own life by drinking a bottle of pesticide.

Green, who blamed himself for allowing the fight to go on and thus for Kim’s death, also committed suicide after his depression deepened.

“What really tortured me that night was it could have been me,” Mancini said in an ESPN special that was shown on the 25th anniversary of his fight with Kim. “I was looking at my hands going, `I can’t believe I did that.’

“My faith in God is the only thing that carried me through that. I said my prayers, `God, please help me to find the answers. I need answers. Help me to find the peace in this.’”

Green apparently never found his answers or his peace.

Maybe there is no common thread that ties Green to Halpern, or Halpern to Gibson. But some things need to be taken into consideration when assessing the pressures that referees occasionally find themselves under.

Take, for instance, the prison sentence recently meted out to disgraced NBA referee Tim Donaghy for conspiring to provide assistance to gamblers, a scandal that threatened to undermine public confidence in pro basketball.

There are sports books in Nevada, and it is not uncommon for large wagers – sometimes into seven figures – to be placed on boxing matches. If approached by anyone attempting to influence a fight’s outcome, a referee or a judge would be obligated to report such a contact to the Nevada State Athletic Commission and to the FBI.

But what if a losing better blamed the referee and threatened to do harm to him or to his family? And what if a boxing ref, like Donaghy, developed a gambling problem that made him susceptible to bribes or coercion?

A referee can work hundred of bouts without incident and all it takes is one tragedy to forever taint him. If Green or Ruby Goldstein were here, you could ask them. Goldstein, who died in 1984, was inducted posthumously into the International Boxing Hall of Fame in 1994. But despite his 21 years of exemplary service, he probably is best known for momentarily freezing in the March 24, 1962, fight in which Emile Griffith battered Benny “Kid” Paret into a coma and, a few days later, death.

Another Nevada referee of note, Joe “Firm but Fair” Cortez, doesn’t have an inkling as to why Gibson took his own life. “Toby and I posed as part of a group photo Saturday at a seminar we did with some doctors,” Cortez said from Hawaii, where he and his family went to celebrate Thanksgiving. “It didn’t seem that anything was wrong with him then.”

But there is stress related to the job that has the potential to become dangerous when it runs headlong into the travails of everyday living. Cortez understands that referees are human beings, too, and subject to anxieties the rest of us face. His daughter was left paralyzed after an automobile accident, and his wife contracted breast cancer. How difficult can it be to have all that on your mind when you’re giving instructions to the fighters before the opening bell sounds?

“With criticism comes hurt,” Cortez acknowledged. “Sometimes it seems as if you’re damned if you do, damned if you don’t. Even when you follow the rules to a `T,’ the fans don’t want to hear that. Fans are fans; they have a rooting interest in a particular fighter.

“Every referee knows what it’s like to have people say he’s no good, he’s biased, he ought to be run out of boxing. Whenever I hear that a referee made a judgment call that is somehow controversial, I’m the first one to pick up a phone and call him to offer my support. See, I know what he’s going through; I’ve been through it.

“Like I always say, you got to have a thick skin to be in this business because the pressure is just tremendous. Fortunately, I can deal with pressure. But Toby … I don’t know what was going on with him when he decided to do what he did. You never know what’s going through someone’s head at any given moment.”