911: whats your emergency
Caller: Yes, there is a black guy leaving a construction site.
911: you should go chase him down with guns and shoot him so he doesnt get away before the cops arrive.
Said no one ever.
They didn't have guns on them to shoot him to prevent escape. They were bearing arms in case needed to defend themselves from violence, such as the suspect attacking them in such a way as to be life threatening, as he actually did.