Ben Crump has represented the families of Tyre Nichols, George Floyd, Breonna Taylor and more.

Ben Crump, in the words of the Rev. Al Sharpton, is “Black America’s attorney general.”

Mr. Crump, the lawyer representing the family of Tyre Nichols, has been the go-to lawyer for the families of Black people killed by the police or others for more than 20 years, including those of Ahmaud Arbery, George Floyd, Tamir Rice and Breonna Taylor.

But it was the killing of Trayvon Martin, an unarmed Black teenager who was fatally shot by a neighborhood watch volunteer in a suburb of Orlando, Fla., that catapulted Mr. Crump into the spotlight. Mr. Crump became a regular on cable news, bringing national attention to the case and motivating a new generation of activists.

“Trayvon Martin will forever remain in the annals of history next to Medgar Evers and Emmett Till as symbols for the fight for equal justice for all,” he said after a jury acquitted the volunteer, George Zimmerman, in 2013.

Two years later, Mr. Crump represented the family of Michael Brown, a young Black man who was shot and killed by a white police officer in Ferguson, Mo. The list continued to grow.

In the years since, Mr. Crump, who has a law degree from Florida State University, has embraced his roles as lawyer and activist.

“We have an opportunity here, America, to really speak to this institutionalized police culture and show that it is not just about white officers or Black officers or Hispanic officers,” Mr. Crump said last week, after murder charges were filed against five former officers in the death of Mr. Nichols. “It’s about police officers having this biased belief that you can get away with doing certain things to Black citizens and brown citizens in America that you cannot get away with white citizens.”

He noted how “the simple encounter” of a traffic stop led to murder and kidnapping charges against the police, adding that Mr. Nichols’s death should lead to substantial changes in policing, including legislation requiring police officers to intervene when they see other officers using excessive force. His team called for the city to immediately disband the police unit involved in the traffic stop that led to his death.

“That is what we’re going to have to do if we’re going to give Tyre Nichols the proper legacy,” Mr. Crump said.