This claim is true. According to NBC News, a 45-year-old man from El Paso County has been charged with attempted first-degree murder after deliberation, attempted first-degree murder with extreme indifference, first-degree assault, including such against an at-risk victim older than 70, and possession of an incendiary device. According to Reuters, authorities said the man yelled "Free Palestine" and "threw incendiary devices into a crowd in Boulder, Colorado where a demonstration to remember the Israeli hostages who remain in Gaza was taking place." Four men and four women between the ages of 25 and 88 were injured as a result.