One month ago, a white police officer pressed his knee into the neck of George Floyd for eight minutes and 46 seconds, suffocating and killing the African-American.
The fatal encounter with Minneapolis police was captured in mobile phone footage recorded by bystanders passing through the junction, where police were responding to a call claiming Floyd, 46, used a counterfeit $20 bill to buy cigarettes.
Two bystander videos showed officer Derek Chauvin applying continuous pressure to Floyd’s neck as he gasped, “Please, I can't breathe.”
He repeated the phrase more than a dozen times before losing consciousness.
He was pronounced dead shortly after the encounter and an independent post-mortem examination showed he died of "asphyxiation from sustained pressure".
The footage of Floyd gasping for air went viral and sparked a global movement for racial equality and police accountability.
Spurred on by the video, a wave of protests crossed the US, renewing demands to overhaul law-enforcement practices.
“It didn’t happen in a dark alley, or a deserted park, or during a traffic stop on highway where cars are whizzing by,” said Tara Huffman, director of the criminal and juvenile justice programme at Baltimore’s Open Society Institute.
"It happened on a city street, with an audience. George Floyd’s audience had a front seat to his execution.”
Two weeks after, a new witness video emerged online and quickly went viral.
In it, African-American man Rayshard Brooks lay lifeless on the ground after being shot twice in the back by a white Atlanta police officer.
The death of Brooks heightened the protests, with activists calling for a drastic rethinking of how policing works.
But in the two weeks between the deaths of Floyd and Brooks, at least 57 others were shot dead by police officers in the US.
In nine of the cases there were signs of mental illness, according to data compiled by The Washington Post.
At least 11 of those deaths were confirmed to be of African-American men.
The staggering scale of police-involved killings in the US is far greater than the select viral moments that garner public attention.
The Post data showed police have shot dead at least 490 people in 2020, or more than two a day this year.
The number is larger when accounting for non-shooting deaths such as Floyd's.
Fatal Encounters, a volunteer-run database monitoring police brutality, counted 959 deaths involving police this year.
For every George Floyd or Rayshard Brooks, there are many deadly encounters with police that go unnoticed.
That these two incidents were captured on video appears to have increased the likelihood of legal action.
In both cases, the offending officers have been charged with murder, which is a rare occurrence.
When allegations of officer misconduct arise, police will conduct internal investigations, which rarely result in discipline.
And it is not uncommon for fired officers to be reinstated through arbitration or to be hired by other police agencies.
Christy Lopez worked in the civil rights division of the US Department of Justice from 2010 to 2017.
Mr Lopez led the team that investigated the police department in Ferguson, Missouri, after the 2014 killing of unarmed African-American teenager Michael Brown by a white officer.
“I have been reviewing written accounts of incidents like this for decades and often it is only when there is a video that there is any chance of accountability, or even attention, regardless of how blatant the police misconduct is," he said.
“There is no question that video prompts action.”
Bystanders' videos can be more valuable for investigations and prosecutions than officers' body cameras, which provide a limited field of view, said Seth Stoughton, a law professor at the University of South Carolina and a former police officer.
Mr Stoughton said body cameras could malfunction and officers sometimes failed to activate them before an incident.
But while there may be benefits to recording police interactions, there is also an emotional toll borne by people of colour who must repeatedly confront violent and tragic footage.
"Trauma happens when a police encounter goes viral," Ms Huffman told The National.
"People, especially black people, and especially black youths, are being traumatised over and over again by these videos.
“Black youth get the message that police are a threat, and black parents have to once again face agonising questions and have agonising conversations with their children.”
The mounting number of police-involved killings in the US has led to calls from activists to defund police departments and redirect the money towards social services.
One reform is co-responder programmes, in which social workers join police when responding to non-violent calls involving mental health, addiction and homelessness.
“Reallocating funds away from the police, and to non-punitive public health and community-based systems and institutions, is an idea whose time has come,” Ms Huffman said.