Atlanta police Sgt. Lisa Keyes said in an e-mail Sunday that the 38-year-old Forrest was shot several times in the back late Saturday night on a street just southwest of downtown. Keyes said there were no suspects.
Fulton County medical examiner Michele Stauffenberg confirmed the case was a homicide and that the autopsy showed Forrest died from "multiple gunshot wounds involving the torso and thigh." Keyes said a police report on the shooting was not immediately available.
Charles Watson, the boxer's manager, said police and witnesses told him that Forrest had stopped at a gas station to put air in his car tire when a man approached asking for money.
"Somehow, Vernon had his wallet out and the guy snatched his wallet and started running," Watson said. "Vernon pursued after him. The guy turned the corner and Vernon didn't see him. He turned around to go back to the car. That's when he started firing."
Watson said Forrest's 11-year-old godson was with him, but had gone into the convenience store and did not witness the shooting.
The death quickly sent a ripple through the close-knit boxing world.
"Vernon was one of the few decent people in boxing," his promoter Gary Shaw told The Associated Press. "I don't know what to say. I'm still in disbelief, I'm still in shock."
Forrest, a native of Augusta, Ga., who lived in Atlanta, was a member of the 1992 Olympic team along with Oscar De La Hoya. The popular fighter later won welterweight and junior middleweight titles and compiled a professional record of 41-3 with 29 knockouts.
"He was one of the most gracious and charitable fighters in boxing and he will be missed by the entire boxing community," said HBO Sports president Ross Greenburg, who helped put on eight of Forrest's fights. "Maybe Vernon's lasting legacy will be for Americans everywhere to rise up and end this kind of senseless violence."
Those who knew Forrest praised his role in launching the Destiny's Child group homes in Atlanta, which work to provide homes for the mentally disabled.
Longtime publicist Kelly Swanson called him "a caring humanitarian who always stood up for what he believed to be the fairness of life."
"It was truly his calling," Swanson said of his work with children. "When he wasn't boxing, this was his full-time job. ... When they would see him, they would just light up, and some of them couldn't even talk. Vernon was very much involved. He'd have some of the kids over to his house on Sundays. They were part of his family."
Swanson said Forrest was not married and had one son, Vernon Jr.
Forrest turned pro not long after the Barcelona Olympics, when he was stricken by food poisoning and lost in the opening round. He won his first world title by defeating Raul Frank at Madison Square Garden for the vacant IBF welterweight belt in May 2001, and less than a year later handed Mosley his first career loss to capture the WBC title.
The smooth-punching Forrest defended the belt against Mosley, winning by unanimous decision six months later, before losing to Ricardo Mayora in January 2003. It was Forrest's first loss, and he'd lose again to Mayorga in a close bout many believe he won.
After taking two years off because of injuries, Forrest embarked on an impressive comeback that included a win over Ike Quartey and a victory over Carlos Baldomir for the vacant WBC junior middleweight title. Forrest defended it once, before losing it in a stunning upset to Sergio Mora in June 2008.
Like a true champion, the soft-spoken yet hard-punching Forrest reclaimed it when he won a lopsided decision last September in what ultimately was his final fight.
"He was a great fighter, a great champion," said Ken Hershman, vice president in charge of boxing at Showtime. "He was coming to the end of his career, but wasn't ready to hang 'em up. He still had a lot of life ahead of him."
There were tentative plans for a title fight against Sergio Martinez, perhaps in October, Shaw said. Plans for an August fight against Martinez were pushed back because of a rib injury, and the delay led the WBC to strip Forrest of his title.
His trainer Buddy McGirt told the AP that he spoke to Forrest last week, and the two were planning to return to the gym on Aug. 1.
"I've been in a daze. I'm at a loss for words," said McGirt, who was awakened early Sunday by the call with the bad news. "When I answered it was his assistant and she was crying, and I knew something happened, man. I just feel so bad."
This is the third high-profile death of a boxing champion in recent weeks.
Hall of Famer Alexis Arguello, the mayor of Managua, Nicaragua, was found dead at his home on July 1 in an apparent suicide. Two weeks ago, popular brawler Arturo Gatti was found dead in a condominium in Brazil. Gatti's wife remains the prime suspect in that case.
"If the saying is bad things come in threes, hopefully we're done with that for a long time to come," Hershman said. "I hope that's the case. I mean, ironically three great people, three great human beings, too. Not a good few months."
McGirt was especially shaken by the death of Forrest, whose wins over Mosley earned him the 2002 Fighter of the Year award from Ring Magazine, and whose kindness outside of the ring earned him the Good Guy award in 2003 from the Boxing Writer's Association of America.
Columnist Scott Michaux interviewed Vernon Forrest after he won undisputed welterweight championship in 2002.