(NewsNation) — “We have seen this all too often in communities all across this country,” Byron Brown, the longest-serving mayor of Buffalo, New York, said after a mass shooting at a supermarket in his community took the lives of 10 people over the weekend.

“This is sadly, a uniquely American phenomenon,” Brown said during an appearance on “Morning in America”. “Urban, suburban, rural, it does not matter. In this particular case, the motive, the reason was hate, was racism. Someone that had a hateful heart and head wanted to kill as many black people as possible.”

According to authorities, 11 Black people and two white people were shot when a white 18-year-old gunman wearing military gear and livestreaming with a helmet camera allegedly entered a Tops Friendly Market with a rifle and opened fire.

As Buffalo and the nation try and make sense of an act that authorities called “pure evil,” Brown appealed for forceful action from Washington, stressing the need for sensible gun control.

“If we want to stop this type of thing from happening in America, the shootings that don’t occur in other countries across the world, we need sensible gun control,” he said.

Following the incident, New York Gov. Kathy Hochul said “wild access to guns” and “unfettered sharing of hate information” online is “a lethal combination”

Hochul said national laws are needed to curb gun access and the online sharing of hate information in the U.S.

According to Brown, those are two things that have to be looked at “very quickly, and very powerfully and persuasively, to stop the kind of carnage that we saw in my city.”

The shooter’s livestream of the attack on social media prompted scrutiny of how fast social platforms react to violent videos.

“The social media companies need to be held accountable and need to do something different,” Brown said. “We cannot allow hate speech and hateful manifestos to go out over the social media. It’s not free speech. It’s un-American, it’s not the American way.”

As the shooting raises more questions than it does answers on racial strife in America, Brown wonders just what kind of influences the shooter was exposed to that germinated that kind of hate.

The suspect had previously threatened a shooting at his high school in June 2021 and was evaluated for mental health treatment, law enforcement confirmed.

“It is just inconceivable to think about what might have been those influences that develop this kind of deranged individual,” he said.

President Joe Biden planned to visit Buffalo on Tuesday, urging unity as a remedy for what he calls “the hate that remains a stain on the soul of America.” 

Buffalo is known nationally and internationally as the city of good neighbors, and numerous groups and government agencies have resources available both to the family of the victims and community members who have been affected by the shooting.

“We are a warm and welcoming community, but we are a strong community,” Brown said. “We will breathe, we will heal and we will move forward as one people, one city, one Buffalo.”

The Associated Press contributed to this report.