NEW : ` ` make a killing , but make it in peace , '' says Eric Garner 's mother . Thousands gather across New York , other major cities . Garner , an unarmed black man , died after a white police officer put him in a chokehold . A grand jury decided not to indict the officer ; Governor Holder announces an investigation .
NEW : `` Make a statement , but make it in peace , '' says Eric Garner 's mother . Protesters gather across New York , other U.S. cities . Garner , an unarmed black man , died after a white police officer put him in a chokehold . A grand jury decided not to indict the officer ; AG Holder announces an investigation .