Stephen Jackson is at the forefront of the fight for justice in the killing of his friend George Floyd ... saying he's going to do whatever it takes to make sure the officers are convicted.
The ex-NBA star revealed this week that he's known Floyd for more than 20 years ... saying they even called each other "twin."
Jackson -- alongside Timberwolves center Karl-Anthony Towns, rappers Bun B and Trae The Truth, and actor Jamie Foxx -- gave an emotional speech at a news conference in Minneapolis on Friday.