Dallas gunman Micah Johnson taunted police and wrote in blood during stand-off

The suspect in the deadly attack on Dallas police taunted authorities during two hours of negotiations, laughing at them, singing and at one point asking how many officers he had shot, the city's police chief has revealed.

Micah Johnson, a black Army veteran, insisted on speaking with a black negotiator and wrote in blood on the wall of a parking garage where police cornered and later killed him, David Brown told CNN's State Of The Union.