Describing himself as "leaning to the right on some issues," the Saints' coach emphatically stressed he is not in favor of current gun laws in the United States, specifically in Louisiana.
"I hate guns," Payton told USA Today Sports.
Smith, 34, was killed Saturday after being involved in a minor traffic accident in New Orleans. Police have arrested Cardell Hayes, 28, and charged him with second-degree murder.
"I've heard people argue that everybody needs a gun," Payton said. "That's madness. I know there are many kids who grow up in a hunting environment. I get that. But there are places, like England, where even the cops don't have guns."
Payton, who lives in New Orleans' Garden District, also railed against the overall violence in the city, saying, "Our city is broken."
"I feel like this is a problem that's been around for a long time," Brees said in an interview with local station WWL Radio. "And it's not just New Orleans, it's nationwide. It's worldwide. It's the way that people treat people. And somehow along the way, we've all become desensitized to the fact that this stuff happens every day and it's OK, or we can just kind of move on from it as if it's gonna happen and it's part of the way things are and there's nothing we can really do about it.
"And listen, it's overwhelming," Brees added. "It's overwhelming when you think about this epidemic, or this problem, of young, mainly young men, killing young men for no apparent reason."
Gentry called on the need "to eliminate such senseless violence in our city," saying he was "totally against" guns.
"I don't want to have what happened the other night, in the Will Smith situation, taint everything about this city," Gentry said Monday night before the Pelicans' game against the visiting Chicago Bulls. "It was a senseless thing. It was ridiculous. The whole gun thing makes me sick to my stomach."
Police said Smith and Hayes argued after Smith's Mercedes was rear-ended by Hayes' Hummer. According to police, Hayes shot Smith and his wife, Racquel, who was taken to a hospital with a leg wound.
Payton, who was Smith's coach with the Saints from 2006 to 2013, went to the accident scene early Sunday morning and joined Smith's family at the hospital.
He told USA Today Sports that he researched the handgun Hayes allegedly used to shoot Smith and his wife, saying, "This thing just stops people."
"It was a large caliber gun. A .45," Payton told USA Today Sports. "It was designed back during World War I. And this thing just stops people. It will kill someone within four or five seconds after they are struck. You bleed out. After the first shot, he took three more in his back. ... We could go online and get 10 of them and have them shipped to our house tomorrow.
"I don't believe that was the intention when they allowed for the right for citizens to bear arms."
Payton, 52, has been the Saints' coach since 2006 and has lived in various New Orleans communities ever since. He lamented recent budget reductions for the city's law enforcement but also cited extensive gun violence in New Orleans' less affluent areas.
"We don't hear this noise when something happens in New Orleans East or in the Lower 9," he said. "Now you creep into the Garden District ... "
Gentry also issued condolences and get-well wishes to Smith's wife and family.
"For us, it's part of our family, because you take the Pelicans and you take the Saints and we're all a part of the family," Gentry said. "Our thoughts and prayers go out to his family and to his wife -- and I hope that she has a speedy recovery -- and then I think we all need to pray for the kids. And hopefully that doesn't define us as a city, because this is a great place to live and got so many great people that are so caring, that that's not who we are here."
Information from ESPN's Mike Triplett and Justin Verrier was used in this report.