A suspected gunman in the killing of nine people at a historic African-American church in South Carolina, ha
s been arrested, Attorney General Loretta Lynch says.
Officials earlier named 21-year-old Dylann Roof as the man they were looking for, after the shooting in Charleston.
The gunman sat in a Bible study meeting for up to an hour before firing.
Six women and three men, including the church pastor, were killed.
Officials have called it a hate crime.
The Justice Department earlier said it would open a federal hate crimes investigation.
Ms Lynch said the Justice Department would look at all the facts and motivations to determine the best way to proceed with any prosecution.
Police said the suspect was arrested at a traffic stop in Shelby, North Carolina.
The arrest came just a few hours after the release of surveillance images of what police described as a young white man arriving at the church an hour before shooting occurred on Wednesday evening.
The killings have sent shockwaves through a community that has already experienced heightened racial tension in recent months.
The shooting two months ago of Walter Scott, an unarmed black man by a white police officer in North Charleston, prompted angry protests. The officer has since been charged with murder.