Former San Francisco 49ers quarterback Colin Kaepernick first protested against racial injustice and police brutality by kneeling down during the United States national anthem in the summer of 2016. Since then, a whole movement has grown around that gesture.
BBC Sport travelled to the US to investigate. Listen again to BBC Radio 5 live's programme, On Bended Knee, and watch a special Newsnight report.
"This is what lynchings look like in 2016."
A video accompanies Colin Kaepernick's Instagram post. It begins as two white police officers wrestle a black man to the floor.One officer appears to cuff the man's hands behind his back. Another, positioned by the man's shoulders, tightly presses his head to the ground.The same officer moves one hand away, reaching for his gun. He points it to the man's chest, and fires.
Alton Sterling, 37, died of gunshot wounds to the chest and back. Pinned down and shot in Louisiana
"Another murder in the streets because of the colour of a man's skin, at the hands of the people who they say will protect us," Kaepernick writes.
"When will they be held accountable?"
The next day, 6 July 2016, another black man is shot dead by a police officer.
Philando Castile, 32, is shot seven times during a traffic stop. He died in the driver's seat with his girlfriend beside him and her four-year-old daughter in the back.
Police dashcam footage shows officer Jeronimo Yanez firing several times into the car. He pulled it over because of a broken brake light.
BBC Sport travelled to the US to investigate. Listen again to BBC Radio 5 live's programme, On Bended Knee, and watch a special Newsnight report.
"This is what lynchings look like in 2016."
A video accompanies Colin Kaepernick's Instagram post. It begins as two white police officers wrestle a black man to the floor.One officer appears to cuff the man's hands behind his back. Another, positioned by the man's shoulders, tightly presses his head to the ground.The same officer moves one hand away, reaching for his gun. He points it to the man's chest, and fires.
Alton Sterling, 37, died of gunshot wounds to the chest and back. Pinned down and shot in Louisiana
"Another murder in the streets because of the colour of a man's skin, at the hands of the people who they say will protect us," Kaepernick writes.
"When will they be held accountable?"
The next day, 6 July 2016, another black man is shot dead by a police officer.
Philando Castile, 32, is shot seven times during a traffic stop. He died in the driver's seat with his girlfriend beside him and her four-year-old daughter in the back.
Police dashcam footage shows officer Jeronimo Yanez firing several times into the car. He pulled it over because of a broken brake light.
