Round like a shot

Going to bed the other night I noticed people in my shed stealing things. I phoned the police but was told no one was in the area to help. They said they would send someone over as soon as possible. I hung up... A minute I rang again: "hello, I called you a minute ago because there were people in my shed. You don't have to worry now, I shot them". Within minutes there were half a dozen police cars in the area plus helicopters and an armed response unit. They caught the burglars red-handed. One of the offices said: "I thought you said you'd shot them!". To which I replied: "I thought you said there was no one available!".