Images of tense encounters between protesters and police officers piled up over the weekend, as authorities intensified their efforts to quell nationwide uprisings, using rubber bullets, pepper pellets and tear gas in violent standoffs that seared cities nationwide. But some officers took different actions, creating contrasting images that told another story about the turbulent national moment following the death of George Floyd, a 46-year-old black man, in police custody in Minneapolis. From New York to Des Moines to Spokane, Wash., members of law enforcement - sometimes clad in riot gear - knelt alongside protesters and marched in solidarity with them. The act has become synonymous with peaceful protests in recent years after football player Colin Kaepernick knelt as part of his protests against police brutality on unarmed black citizens. A video circulating widely on Facebook captured two people in uniform joining a kneeling crowd in Queens. "Thank you!" cheered members of the crowd. The officers remained as a circle of people began to chant names of black Americans killed in infamous recent cases. "Trayvon Martin!" they called. "Philando Castile!" Cheers erupted, too, in the Iowa capital as Des Moines officers took a knee behind a police barricade. Acceding to the demands of protesters brought a rebuke in some places. In downtown Washington, a black officer who knelt was yanked from the crowd by his supervisor, and he returned standing to the line forming to hold back the demonstrations.