A Raleigh, North Carolina, police officer on Monday killed a man who was fleeing arrest, authorities said, and a local TV station reported protesters chanting "black lives matter" gathered at the scene.Raleigh police did not give the race of either the officer or the dead man. But a black woman who identified herself as the victim's mother told local television the officer was white and that her son was shot in the back as he ran away.Raleigh Police Chief Cassandra Deck-Brown told reporters that the suspect was running from an officer who sought to arrest him for a drug offense. He was shot near a convenience store just after 12 p.m. A gun was found near the body.The deaths of African-Americans, many of them unarmed, at the hands of police over the past few years have sparked a debate around the United States and on the presidential campaign trail. The Black Lives Matter movement sprang up following deaths in Ferguson, Missouri, and elsewhere.A crowd gathered at the scene of the shooting in Raleigh, North Carolina's capital, and chanted "black lives matter," according to WTVD-TV in Raleigh. The American Civil Liberties Union's North Carolina chapter posted on Twitter that a vigil would be held for the victim.