In March 1991, black motorist Rodney King was beaten by white police officers in Los Angeles - and it was caught on camera.
The trial and subsequent acquittal of the officers involved sparked violent riots in a community that felt there had been no sense of accountability. The outcry eventually forced changes to the Los Angeles Police Department.
Three decades later in Minneapolis, the death of George Floyd at the hands of police is also filmed by bystanders. Protests erupt in cities across the US, and later, around the globe.
Now, as a city awaits the trial and its aftermath, here's a look back at another influential American courtroom, some 30 years ago, thanks to newly released sketches from the King trial.
The black-and-white witness footage of four white officers beating and kicking King nearly to death was one of the first instances such brutality had been filmed.
The community had been grappling with excessive use of force by the majority white police department for years before the King incident - but now, there was proof.
A year later, in 1992, acquittal of the officers involved that sparked massive unrest in Los Angeles. Tensions over longstanding race and economic inequalities boiled over. Shopping centres were looted and burned. Fifty-four people died. Thousands were arrested.
Following that grainy video of King's beating were many more incidents of police brutality against black Americans. Dozens have made national headlines, led to protests, movements, calls for real change.
These courtroom sketches, recently acquired by the US Library of Congress, capture the tense and febrile atmosphere of the trial.
The footage and outcry over George Floyd's death has perhaps been the most influential in recent years.
The George Floyd trial begins on 8 March, with jury selection. Twelve jurors will be seated to decide the case.
Arguments are due to start on 29 March and are expected to take at least one month.