Correction: An earlier version of this editorial incorrectly gave Rodney King’s age as 34 when he was beaten along a Los Angeles highway by police officers. King, who died June 17 at age 47, was 25 at the time of the 1991 incident. (It occurred one month before his 26th birthday.) The following editorial has been corrected.

RODNEY KING has died, 21 years after a brutal assault by Los Angeles police officers made him a household name.

On March 3, 1991, King, then 25, was speeding on Interstate 210 at more than 100 miles per hour. Just released from a two-year sentence for robbery, he had been drinking and was well aware that he would be found in violation of his parole if stopped. When he did finally pull over after an eight-mile police chase, he acted aggressively with the officers. What happened next, however, sent shockwaves through the country: Recorded by a bystander on home video, officers tased and kicked Mr. King and bludgeoned him with metal batons more than 50 times.

After these images aired worldwide — and especially after riots erupted in Los Angeles after the acquittal of several of the officers — Rodney King became a reminder of police brutality and of the persistence of institutionalized racism. Two decades later, how much has changed?

Some good did come of Mr. King’s suffering. In subsequent years, the Los Angeles Police Department — mostly under the direction of chief William Bratton — actively pursued a model of community policing that focused on regaining the trust of minority communities wary of racial profiling and the needless reliance on force. Community policing has been largely successful in Los Angeles and has since been implemented in other cities. The home video, too, was a reminder to police everywhere of an emerging culture of public accountability and the demands it makes of officers.

But many of the fears and suspicions that fueled the riots of 1992 understandably persist. In February, in the wake of the Trayvon Martin shooting, police initially released George Zimmerman without charge; many saw race as the primary explanation of that decision. In New York City, police stop-and-frisk practices disproportionately target minorities: statistics from the New York Civil Liberties Union show that, in the last decade, of the roughly 700,000 people stopped each year, almost 90 percent are either black or Latino. Figures like these are what drive thousands of people to public protests against police authority, as in New York this past weekend.

Earlier this year, Mr. King told the Los Angeles Times he was written into a drama he wanted no part of: “I never went to school to be ‘Rodney King.’ ” There’s still work to do to ensure that he didn’t play the role for nought.