ExMinneapolis police officer charged with murder.

The white Minneapolis police officer who pressed his knee into George Floyd’s neck as he begged for air was arrested Friday and charged with murder, as authorities imposed overnight curfews to try to stem violent protests over police killings of African Americans that have spread from Minneapolis to cities across the country.

Protesters smashed windows at CNN headquarters in Atlanta, torched a police car and struck officers with bottles. Large demonstrations in New York, Houston, Washington, D.C., and other cities ranged from people peacefully blocking roads to clashing with police.

In Minneapolis, thousands of protesters marched through downtown as an 8 p.m. curfew ticked past and encircled a police precinct station. “Prosecute the police!” some chanted, and “Say his name: George Floyd!”

Protests roiled the country the same day Officer Derek Chauvin, 44, was charged with thirddegree murder and seconddegree manslaughter. He also was accused of ignoring another officer who expressed concerns about Floyd as he lay handcuffed on the ground, pleading that he could not breathe as Chauvin pressed his knee into his neck for several minutes. Floyd, who was black, had been arrested on suspicion of using a counterfeit bill at a store.

Chauvin, who was fired along with three other officers who were at the scene, faces more than 12 years in prison if convicted of murder.

An attorney for Floyd’s family welcomed the arrest but said he expected a more serious murder charge and wants other officers arrested, too.

Prosecutor Mike Freeman said more charges were possible, but authorities “felt it appropriate to focus on the most dangerous perpetrator.”

Demonstrators clashed with officers in New York and blocked traffic in Houston and San Jose. In Atlanta, demonstrators smashed police cars, broke into a restaurant and spraypainted the logo sign at CNN’s headquarters, where hundreds confronted police. At least three officers were hurt.