DETROIT — Black activists believe the police killing of George Floyd and the nationwide civil unrest that followed could be the catalyst for overhauling the criminal justice system.

Following Saturday's massive demonstrations against racism and police brutality, some are pushing for incremental change, such as requiring more rigorous training, reviewing policies and mandating that officers live in the communities in which they work to deepen their relationship with residents. But others are advocating for more sweeping responses, such as defunding law enforcement agencies or even dismantling police departments.

Tens of thousands of people marched in places from coast to coast Saturday in what was perhaps the largest one-day mobilization since Floyd died on May 25.

"What we're facing is a real reckoning on a lot of levels," said Alicia Garza, co-founder of Black Lives Matter. "This (coronavirus) pandemic pulled back the curtains on decades of disinvestment, decades of devaluing and also now one of the major issues that black communities face is violence at the hands of the police."

Many activists believe the unrest could be an opportunity to press Democratic leadership, including presumptive presidential nominee Joe Biden, to address criminal justice in a deeper way. Floyd's family and civil rights leader the Rev. Al Sharpton have announced a march on Washington in August to call for a federal policing equality act.

Biden in recent days has condemned police brutality and urged fundamental change. Weeks ago, he released a plan called "Lift Every Voice" to address issues important to the black community, including a proposal to expand the power of the justice system to address "systemic misconduct" in police departments and prosecutor offices.

"This is a national crisis and we need real leadership right now, leadership that will bring everyone to the table so we can take measures to root out systemic racism," Biden said last week as protests roiled the country. "It's time for us to take a hard look at the uncomfortable truths."

But some want him to go further.

"Black communities are under assault, we are under attack and it's from all sides," said Color of Change president Rashad Robinson. "He (Biden) has an opportunity to help by actually being more forthright and visionary about what he's going to achieve and how he's going to undo the barriers standing in the way."

The Minneapolis City Council is considering disbanding the Minneapolis Police Department as one response to Floyd's killing. The city announced an agreement Friday that would ban the use of chokeholds and require police to report and intervene when they see unauthorized use of force.

"There's a cry for a real meaningful change, and it starts with justice for George Floyd, but it can't end there," Minnesota Attorney General Keith Ellison told The Associated Press before becoming the special prosecutor in Floyd's case. "We need new, fundamental change, and it needs to be from the top to the local community."

Days after that interview, Ellison upgraded charges against fired Minnesota officer Derek Chauvin and charged three other policemen with aiding and abetting murder.

The political ramifications of the unrest could also be significant, particularly among potential younger voters who feel the repeated instances of police misconduct are indicative of a "system that wasn't created for or by them," according to Minnesota-based Black Visions Collective organizer Oluchi Omeoga.

Biden, a moderate, won the Democratic primary because of his wide support among African American voters as a whole. But younger African Americans were more likely to support his liberal challenger Sen. Bernie Sanders, favoring him 44% to 38%, according to AP VoteCast surveys in 17 states.

Omeoga doesn't support the political system and doesn't think any candidate truly speaks to the black community. The organizer had no plans to vote in November and said others have expressed similar feelings.

"I don't see black folks' liberation through an electoral politics lens," Omeoga said. "The pandering that's happening in this moment by politicians is because they understand the system is unstable. People are questioning the system."

But activists like Phil Agnew are fighting to ensure that younger activists and voters find a way to let their voices be heard in the November election. Agnew said he supports the idea of younger voters challenging the political system.

"But to sit out in the game of life and become a spectator in your own life is untenable for me," Agnew said. "We've got to start showing the power of engaging wiser and smarter in political processes."

Agnew, who co-founded the Dream Defenders in 2012 after Trayvon Martin's killing and was a senior adviser to Sanders' campaign, said he believes black people cannot afford four more years of President Donald Trump, who has threatened to use the Insurrection Act of 1807 to quell the civil unrest. Agnew believes that many black voters will go to the polls in November to oppose Trump, but he warned that their votes cannot be taken for granted.

"Many people in the country are just now seeing what is daily life for black people," Agnew said. "The onus right now is on Joe Biden to make a compelling case to young people or black people that he is going to be a president that represents their values in the White House."

Meanwhile, public health experts say it's time for the nation to treat police brutality as a public health hazard.

Riana Anderson, assistant professor at the University of Michigan, said a "generational thumbprint" of oppression and systemic racism has culminated into this moment where black Americans are fighting not only a global coronavirus pandemic that has disproportionately killed them but also police brutality, which has afflicted them in the centuries following slavery.

"To the extent that we can absolutely, unequivocally point to the disproportionate use of violence and fatal force that police use for black people and our native brothers and sisters as well, it is a public health hazard on many levels," said Anderson, who teaches health behavior and studies racial discrimination.

To help save or improve the lives of black people, Anderson said, public health professionals need to "advocate for the defunding or at least the deconstruction of the current police system that we currently have because it is in fact endangering the lives of black people."