2nd LD Writethru: White gunman killing 9 at black U.S. church arrested

The white gunman suspected of killing nine African-Americans in a "hate crime" shooting in the southeastern U.S. city of Charleston, South Carolina, was caught on Thursday, law enforcement said.

Dylann Roof, a 21-year-old white man of Lexington, South Carolina, was taken into custody in Shelby, North Carolina during a traffic stop, said Charleston police chief Gregory Mullen at a press briefing.

"We have a lot more investigation to do to find out why this happened," said Mullen.

It was still unclear if the shooter targeted any individual.

"We don't know if anybody was targeted other than the church itself," said Mullen, adding that officials believed that Roof acted alone.

Earlier Thursday, U.S. Attorney General Loretta Lynch announced that the U.S. Justice Department had already opened a hate crime investigation into this shooting incident at the Emanuel African Methodist Episcopal Church, one of the most prominent black churches in the United States.

According to the police, Roof stayed at a prayer meeting for almost one hour Wednesday night before opening fire. A law enforcement official was quoted by the U.S. TV network CNN as saying that witnesses told them that the suspect said he was at the church "to shoot black people."

Nine people, all black, were killed in the shooting spree and three people survived, including a female. She was quoted by local media as saying that the shooter told her he let her live to tell everyone else what happened.

"The only reason someone could walk into church and shoot people praying is out of hate," said Charleston Mayor Joe Riley during a press conference on Wednesday night.

Built in 1891, the church has one of the largest black congregations in the region, said the website of the church. Endite