A Brooklyn man who worked as an advocate against gun violence was fatally shot while in Miami last weekend. Lavon Walker of Crown Heights was gunned down outside of a diner on Miami Beach's Ocean Drive at roughly 7 a.m. Sunday.

In a recent interview with Al Jazeera, Walker admitted to once leading a life of crime. “I was out here everyday sellin’ drugs, robbing cars, robbing stores, gang-bangin’, hanging with the crew,” he told the news organization in August. “I was out here jumping people, fighting people, you know, whatever we had to do.” But in 2010, Walker turned his life around and worked to co-found Save Our Streets, a non-profit dedicated to ending violence across Bed-Stuy and Crown Heights. In the years that followed, Walker often walked the streets with a group of fellow activists, talking to neighbors and mediating conflicts before they took a turn towards violence.

“We find out what their needs are — anything that’s going to gear them or shift them to a different mentality toward gun violence,” he told the Times in 2010. “We become like their bigger brothers, even closer than their fathers.” Walker had been married with two young children. (Crown Heights Community Mediation Center director Amy Ellenbogen told Miami New Times that Walker was down in Miami "to clear his head after going through a number of personal tragedies.")

As of Monday, local detectives had yet to uncover a motive for Walker's killing, according to Miami New Times. Officers are searching for three men they believe to be involved in the shooting who were seen fleeing the diner in a vehicle.

"He's a superman, he's a superman," Save Our Streets Co-Founder Derick Scott told ABC7. "Lavon was a strong young man...that's why he was loved."

Save Our Streets will hold a candlelight vigil for Walker tonight (Tuesday) at 7 p.m. in front of 256 Kingston Avenue in Crown Heights. In a statement posted to their website, the organization expressed collective grief at the news of his murder. "To us in the office, he was our heart. He was always smiling, cracking jokes and keeping us honest. He saw the vision for a violence-free Brooklyn."

Another of Walker's colleagues, Kenneth Edwards, 43, remembered him to the Daily News as an unselfish man of faith devoted to his community. "Lavon took a stance against what was happening among men and women in the same neighborhood he grew up in," Edwards said. "He turned his life around and was making a difference.”