More shocking bodycam footage, more fatal shootings by officers, and a murder trial nearing its conclusion -- public trust in the US police has seldom been more strained.

Video evidence showing apparent wrongful use of deadly force has been piling up, fueling a fierce debate on policing across the United States.

"I am a Black man, and I know from experience that the police just aren't professional and the leadership they get isn't right," said Darnell Squire, 46, who sells T-shirts and baseball caps from a street stall in a Minneapolis suburb.

"They aren't around to protect the community, or to make people feel safe, whatever they say -- that has been clear since I was a child.

"I don't trust promises from the government about things changing, and I don't trust the system or the courts. For me, the problem starts at the top."

In a court in Minneapolis, former officer Derek Chauvin is on trial for murder over the killing of George Floyd, with closing arguments next week before the jury delivers its verdict.

As the trial examined grueling video of Floyd dying while Chauvin knelt on his knee, outside the courtroom, fresh examples of police killings have stoked anger and protests.

People pass by protest slogans opposite the courthouse in Minneapolis, Minnesota where former police officer Derek Chauvin is on trial
People pass by protest slogans opposite the courthouse in Minneapolis, Minnesota where former police officer Derek Chauvin is on trial AFP / Kerem YUCEL

An officer who stopped young Black man Daunte Wright in a Minneapolis suburb last Sunday shot him dead in his car after mistaking her Taser for a gun -- all caught on bodycam.

In another case, Chicago police on Thursday released graphic footage of an officer shooting dead 13-year-old Adam Toledo in a dark alley last month, apparently suspecting he had just dropped a gun.

"I will feel the same even if Chauvin is convicted -- this is a long fight," said Selena McKnight 46, a local activist in Minneapolis who regularly attends protests against police misconduct.

"Just look at the videos that come out every day. We will keep fighting. The trial is just one case, and this battle is not over until justice is always served."

The images of Floyd, Wright, Toledo and others dying at the hands of police have been contrasted to officers dealing with aggressive white men.

Demonstrators hold candles and signs ahead of an evening curfew in front of the Brooklyn Central Police Station outside Minneapolis, near where a policewoman shot dead Daunte Wright
Demonstrators hold candles and signs ahead of an evening curfew in front of the Brooklyn Central Police Station outside Minneapolis, near where a policewoman shot dead Daunte Wright AFP / Kerem Yucel

On Wednesday, in a town outside Minneapolis, an officer was assaulted with a hammer and dragged at high-speed by a vehicle driven by a white, 61-year-old man.

The suspect, who is accused of attacking shop staff who asked him to wear a Covid-19 mask, rammed a police car and drove off with the officer hanging onto his car.

No shots were fired, and the man was later arrested.

"Was that man shot? No, of course not. That tells you all you need to know about police prejudice," said McKnight.

"We might think that all this video footage can make a difference, but it just shows what we all know has been going on for a long time."

Ahead of the Chauvin trial verdict, the United States is braced for potentially violent protests if he is acquitted of murder.

Downtown Minneapolis has been largely boarded up and deserted during the trial, with armed National Guard troops patrolling in armored vehicles.

On Friday night there were new protests in Brooklyn Center, the suburb where Wright was shot, with about 500 people gathering before police moved in to break it up.

Officers said some protesters came wielding shields and baseball bats, while glass bottles were thrown. About 100 people were arrested, public safety officials said.

There were also protests over the death of Toledo in Chicago, where several hundred turned out.

"I fear the police, not Covid-19," said Minneapolis resident Tesfaye Habte, who was born in Ethiopia.

"If I am driving and I see them, I worry they will shoot me because of my color. It seems to have got worse in recent years in this city.

"With the protests, both sides are doing bad things.

"America is democracy, the constitution and free speech, but the police are very aggressive and inhuman. I follow this trial and I am worried."