City councils and state legislatures around the country are considering dramatic changes to policing, but a big obstacle to police reform is often police officers themselves and the unions that represent them.
That's especially true in Minneapolis, where many residents are calling for the controversial head of the police union there to resign while some officers appear to be breaking ranks.
The police killing of George Floyd in Minneapolis on May 25 has sparked daily protests across the country against police brutality and racial inequities. Those marches and demonstrations demand broad changes to policing, but protesters in Minneapolis often focus on one cop in particular, chanting "Bob Kroll Must Go!" and "Fire Bob Kroll!"
Lt. Bob Kroll is the controversial head of the Minneapolis Police Federation, the union representing the more than 800 police officers in this city. On Friday evening, more than a thousand people protested outside the union headquarters, one of several protests in recent weeks that has targeted the police union.
"Bob Kroll is as racist as they come!" shouted Minneapolis civil rights attorney and activist Nekima Levy Armstrong to the cheering crowd Friday. "And his evil has been allowed to fester inside the Minneapolis Police Department!"
When people here talk about a rotten police culture and the community's lack of trust in police, many point to the union and the veteran cop that leads it as a major reason.
"Bob Kroll is the president of this union, but he's also a cartoon character, frankly," said Michelle Gross, president of the group Communities United Against Police Brutality. "He utters racist garbage constantly ... and he's been a brutal cop."
Gross points to Kroll's many comments over the years that she and others view as racist. He was named in a 2007 racial discrimination lawsuit against the police department filed by five black officers, including the current chief, Medaria Arradondo, who alleged he called then Rep. Keith Ellison, who is black and Muslim, a "terrorist," and that he allegedly wore a white supremacist group's patch on his motorcycle jacket. Over his 31 years on the force, there have been 30 complaints filed against Kroll, who has been suspended and demoted by the department, and sued several times for use of excessive force.
"People are very, very sick and tired of the way that he vilifies victims of police and defends killer cops," Gross added.
In a letter to the rank and file a week after the killing of George Floyd, Kroll vowed to fight the firing of the four officers criminally charged in Floyd's death. He made no mention of Derek Chauvin kneeling on Floyd's neck for nearly nine minutes but he did mention Floyd's "violent criminal history."
He called the protests a "terrorist movement," and Kroll criticized political leaders' response as "despicable behavior," saying police officers were being made "scapegoats."
Minneapolis Police Chief Medaria Arradondo this week announced he is pulling out of contract talks with the union and looking for ways to restructure the contract to include greater transparency and accountability as part of a broader push to reform policing.
When a reporter asked if negotiations would be helped if Kroll stepped down, the chief sidestepped the question. Asked if he thought Kroll could change, Arradondo said, "We have to look into our hearts, what's in our best interests, so I hope he will do the same."
Kroll did not return calls seeking comment. The police federation's phones are disconnected; its website, Facebook page and other social media accounts have been taken down. Kroll even called police on a Washington Post reporter who went to his suburban home seeking comment.
Despite the silence, Kroll's presence looms large.
In a video conference call with reporters this week on efforts to revamp policing, Minneapolis City Council President Lisa Bender said the union stands in the way.
"The Police Federation is a clear barrier to change," she said. "And that is the crux of any short-term changes within our department that they have opposed for years."
But now some officers are breaking ranks with Kroll and the union. Fourteen signed an open letter to the city saying, "We wholeheartedly condemn Derek Chauvin," the officer charged with Floyd's murder. The officers say they represent the vast majority of the Minneapolis police force, and wrote that they "stand ready to listen and embrace the calls for change, reform and rebuilding."
"The fact of the matter is these officers are heroes and more need to follow," said former Minneapolis Mayor R.T. Rybak, who is now president and CEO of the Minneapolis Foundation, a philanthropic organization focused on racial, social and economic equity, among other community improvement efforts.
Rybak, who served as mayor from 2002 through 2013, knows some of the officers signing the letter well; two of them served in his security detail.
"What was so important about  cops putting out a letter and speaking as human beings to the human beings they serve," said Rybak, "is that finally we're reaching across the lines that I think for too long have held the police away from the people they're supposed to protect and serve."
But others here are skeptical.
Community leaders and protesters point out that Bob Kroll was elected and reelected police union president by wide margins. Last year, he didn't even have an opponent in winning his third two-year term, suggesting his support inside the department runs deep.
"I want you to understand that Bob Kroll did not come out of thin air," said Jaylani Hussein, head of the Minnesota chapter of the Council on American-Islamic Relations at a rally this week. "Bob Kroll was voted in by the people who are supposed to protect us."
Regardless of where police officers stand, "reform is going to take place in policing whether police choose to participate or not," Rybak said. "They need to dramatically change their leadership and acknowledge how wrong some of these things are. If not, this change will happen, whether police choose to be part of it or not."
Across the country, Bob Kroll is not an anomaly in police unions. There are similar controversial leaders of police unions in Chicago, Philadelphia and several other cities. And that's why, so many reform advocates say, this time, police departments cannot simply be changed. Cities need to dismantle them and start over.