It was late and Charlie was about to climb into  bed when his wife informed him that there was a light on in their garden  shed. Charlie started to go outside to turn off the light but noticed  some people in the shed who were busy stealing his things.                      
He ran back inside right away and called the cops,  who asked him "Are there any intruders in your house?" to which Charlie  replied no and explained his circumstances. The cops told Charlie that  all patrol cars were otherwise occupied, and that he should just lock  his door and a uniformed cop would be at his house when one was free.                      
Charlie answered, "Alright," hung up, waited 30 seconds, and then called the cops again.                      
"Hello, I just called a short while ago because  there were people stealing things from my shed. I want to let you know  that they're not a problem anymore because I've just shot every one of  them."                      
Charlie then hung up the phone. In five short  minutes, three patrol cars, a SWAT team, and an ambulance arrived, and  Of course, the cops caught the burglars in the act.                      
One of the cops snapped at Charlie: "I thought you said that you shot every one of them!"                     
"I thought you said there were no patrol cars free!" Charlie answered.