It appeared a so-called butt dial landed the pair in jail after Fresno police followed the clues they overheard to the crime scene, ABCNews.com said Sunday.
"I have never heard of something like this," Police Sgt. Jaime Rios said. "There have been times where the dispatcher hears something like this, but never has a call come in before a crime being committed and staying on all the way to the end."
Nathan Teklemariam and Carson Reinhart, both 20, allegedly spoke about scoring drugs as they drove around with the 911 dispatcher listening in.
One of the voices on the phone mentioned having a hammer ready. A short time later, the sound of breaking glass was heard and one man reported finding a bottle of prescription medication.