NEW : Protesters rally in New York , Denver , Baltimore and Detroit . NEW : Protests are held at the White House. Obama urges `` calm reflection , '' asks Americans to reflect on toll of gun violence . `` We 're leaning in and depending on you this morning , Leaders call for protests to remain peaceful , push for change .
NEW : Protesters rally in New York , Denver , Baltimore and Detroit . NEW : Protests are held at the White House. Obama urges `` calm reflection , '' asks Americans to reflect on toll of gun violence . Leaders call for protests to remain peaceful , push for change .