Once again, the nation and the world have watched violence erupt following the police shooting death of an African-American man.

The weekend shooting of 23-year-old Sylville K. Smith in Milwaukee prompted demonstrations that turned ugly when six businesses and several cars were torched. An additional person was shot, and several officers were injured.

Gunplay and arson are never, ever the right way to address police-community tensions and conflicts. Such violence only destroys pockets of already challenged neighborhoods and leaves good neighbors pondering whether to rebuild or abandon the communities. And scenes of flames rising from storefronts and police cruisers divert needed attention away from efforts to root out bad cops, improve police-citizen relations and reduce crime.

In this latest case, it's critical that Milwaukee authorities release any video evidence of what happened. Milwaukee's police chief has said Smith was shot and killed by an officer Saturday afternoon after he turned toward the officer with a gun in his hand. City officials said that the officer was wearing a body camera and that the footage shows Smith with a gun. The public needs to see that evidence sooner rather than later.

This time, both the victim and the officer who shot him were black, casting doubt on whether the incident was racially motivated. Many of the protests across the nation — particularly those that led to the Black Lives Matter movement — involved white officers killing black men. Yet the incident still leaves open questions about police department cultures that encourage use of excessive force against people of color.

In response to two evenings of violence Saturday and Sunday, Wisconsin Gov. Scott Walker put the National Guard on standby. That allows local law enforcement to call in state help if and when it is needed. And consistent with a wise state law, the Wisconsin Department of Justice will conduct the investigation into the shooting because the case involves a Milwaukee police officer.

Community outrage over police misconduct is fueled by decades of poor relationships and mistrust between police and black communities — in Milwaukee, in Minnesota and elsewhere across the nation. While the anger and frustration of protesters are understandable, gunfire, burning buildings and destroyed vehicles won't solve any problems. The frightening violence only hardens attitudes against protesters and their important goals.

As we have argued previously, such concerns are legitimate — as is the right to push for change through nonviolent protest. But demonstrations must be peaceful and respectful of public safety so the tough work of building trust between community and police can be advanced.