Al Sharpton denounced the shooting of two LA deputy sheriffs. He also condemned violence in black neighborhoods. To some, it seemed like Sharpton had an amazing and recent transformation. This is not true.

Sharpton has repeatedly criticized gun violence.

From 2014

CHICAGO (WLS) -- The cycle of violence gripping parts of Chicago has community leaders, police, politicians and religious leaders calling for action.

With Chicago's violence making national headlines, a group led by Reverend Al Sharpton plans to convene an anti-violence summit of national civil rights leaders in Chicago.

"People may say we've had summits before," National Action Network Illinois Chair Reverend Gregory Livingston said. "But it's like treating a cold or like treating some kind of virus. Even if you treat it once - doesn't mean you don't keep trying to treat it."

https://abc7chicago.com/stop-the-violence-gun-chicago-shooting/173732/

Sharpton's message is no different than anti-violence message that have come from the black community. Black people have spoken out about violence in their neighborhoods, only to be asked why they don't speak out about violent crime

As noted by Ta-Nehisi Coates

There is a kind of sincere black person who really would like to see even more outrage about violence in black communities. I don't think outrage will do it at this point, but I respect the sincere feeling. 

And then there are pundits who write more than they read, and talk more than they listen, and prefer an easy creationism to a Google search.

https://www.theatlantic.com/national/archive/2012/04/why-dont-black-people-protest-black-on-black-violence/255329/