The person in the robbery video looked just like him. The robbery gun looked like a Colt Woodsman type of target pistol though it could be a different brand. When he was pulled over a pistol was on his right leg, but it was partially obscured in the car photo. If it was the same type that would be another bit of correlation. Not a CCW type gun and the county sheriff said he had never applied for a CCW permit. The girlfriend lied when she said they were pulled over for a burned out tail light. They were pulled over because they were only a few blocks from where the robbery happened and he looked like the robber.
That was the county where the shooting occurred (Ramsey). A local TV station has since confirmed that Castile had a CCW permit issued in Hennepin County.
If the cop ran the plates and there was no note of irreverent having a,permit, then the cop would have good cause to be everything when the decedent said he had a permit he lacked and possessed a gun. At that point any suspicious move by a very dubious individual would cause a cop to take serious action.