America on Monday was picking up the pieces from a weekend of gun violence that – outside the cost of lives – has refocused the country’s leadership on the toxic interplay of political ideology and easy access to handguns and battlefield weapons.

In the most recent case, two people were killed Sunday and at least three others hospitalized after a shooting at a large Houston, Texas, flea market. In California, also on Sunday, at least one person died and five were wounded – including four listed in critical condition – after a shooting at a church with a predominantly Taiwanese congregation in Orange county, south of Los Angeles.

In Chicago, Mayor Lori Lightfoot enacted a weekend curfew for unaccompanied minors at a city park after a 16-year-old boy was killed there. At least 33 people were shot, five fatally, in weekend violence across the city, police said.

The shootings, each horrific in their own way, punctuated the weekend’s main horror: an 18-year-old espousing white supremacist ideology who went to an African American neighborhood in Buffalo, New York, on Saturday and – in less than two minutes – gunned down 13 people at a grocery, killing 10.

That shooting – one of the deadliest racist massacres in recent memory – has renewed scrutiny on internet-promulgated hate speech, access to assault-style guns and body armor, and the inability of law enforcement authorities, elected politicians, religious leaders and the commercial sector to stop such violence from recurring.

In the Buffalo shooting at Tops Friendly grocery, white suspect Payton Gendron is accused of specifically targeting a Black neighborhood and taking aim at Black victims – shoppers, grocery workers and a security guard.

He had purportedly made threatening comments that brought police to his high school last spring, raising questions about whether authorities botched an opportunity to short-circuit Saturday’s killings.

Gendron was never charged with a crime, and investigators had no further contact with him after his release from a hospital where he was mentally evaluated for about 36 hours.

Buffalo Police Commissioner Joseph Gramaglia said the threat Gendron had made was “general” in nature and unrelated to race. “Nobody called in,” he said. “Nobody called any complaints.”

New York is one of several states that, in recent years, have enacted “red flag” laws which are intended to prevent mass shootings, but they rely on a legal petition to temporarily seize people’s firearms, or prevent them from buying guns.

Federal authorities, led by the FBI which is investigating the attack as a hate crime, have said they are working to confirm the authenticity of a racist 180-page document, purportedly written by Gendron, that laid out a plan to terrorize nonwhite, non-Christian people.

In a Twitch livestream video of the attack, Gendron allegedly trains his gun on a white person behind a checkout counter before apologizing and moving on.

A purported screenshot of the video circulating online showed the N-word scrawled in white, along with the number “14”, which is an apparent reference to this 14-word white supremacist phrase: “We must secure the existence of our people and a future for white children.”

Gendron, the Buffalo police commissioner Gramaglia said, planned to continue his assault in the surrounding neighborhood. But he was apprehended outside the grocery after removing his body armor and setting down his Bushmaster rifle with an extended 70-round magazine.

“This individual came here with the express purpose of taking as many Black lives as he possibly could,” the Buffalo mayor, Byron Brown, said Sunday.

Representing families of the massacre victims, renowned civil rights attorney Ben Crump told reporters at a news conference Monday that cable news pundits who have spoken fawningly of the same extremist ideology embraced by the alleged shooter should be held accountable.

The manifesto attributed to Gendron talks about the racist theory that Democrats are pushing open immigration policies to “replace” Republican voters with people of color and retain control of the country’s levers of power.

Crump called pundits airing the ideology on mainstream news channels as “accomplices”.

“Even though they might not have pulled the trigger, they loaded the gun,” he said.

Released, recorded radio transmissions between emergency services showed the speed of the Buffalo massacre and how little time authorities had to intervene. Police had Gendron in custody within six minutes of being alerted to the attack, yet 10 people were still killed.

“Radio, send as many cars as you possibly can,” a responding officer says at about 2.33pm. Less than 30 seconds later, firefighters radioed in that there were at least three people down on the ground and that police “have him” about 20 ft from where they were. At 2.36pm, police reported they had arrested the suspect and confiscated a gun.

But the shooting has brought, as many times before, questions about what authorities can do to confront individuals espousing violently racist intentions before they act on them. And it has brought pressure on social media platforms to flag content posted on their sites.

Before the 2018 massacre of 17 students at a high school in Parkland, Florida, and the killings of more than two dozen people at a Texas church in 2017, authorities had received information indicating the assailant’s violent intent or history.

On Sunday, New York governor Kathy Hochul promised action on hate speech that she said spreads “like a virus”. President Biden is expected in Buffalo on Tuesday to meet with victims’ families. Those slain included an 86-year-old woman who had just visited her husband in a nursing home, a man buying a cake for his grandson, and a church deacon helping people get home with their shopping.

As political figures visited the area over the weekend, some said it was urgent to separate the bonds between gun ownership and religious faith or extremist ideologies.

But for many in the targeted Buffalo community, Gendron’s intent wasn’t the salient problem – it was how the shooting was rooted in US social history.

“The present is the past – same thing,” community activist Marietta Malcolm said. “Don’t think like this is an isolated incident, or act like we haven’t had 300 years of it. Every time people say racism doesn’t exist, somebody does something to prove that it does.”