At 2:52 a.m., Mashburn typed, "Amanda I need you to call me an ambulance."
One minute later he typed, "I am in Gladstone, Mo at the Kendallwood apart complex off Antioch."
At 3:26 a.m. an AT&T dispatcher named Gracie responded, "Can u give us an exact location we have the address"
According to court documents, Gladstone police were sent out at 3:12 a.m. and found Mashburn at 3:42 a.m. --
30 minutes later -- with lights flashing and the orange beacon turned on as he stated in his messages.
Ben Marr is a manager at National Audio Sound and Security in Independence. He said most GPS systems can pinpoint a location in a matter of seconds.
"It lets you know immediately where it is," he explained. "Most of these use cell phone towers as well as GPS tracking and because of that they can often pinpoint the location with a couple of seconds either on a smart phone or on a laptop."
Bryan J. Middlemas, 35, was charged with first-degree murder in Mashburn's death.
He pleaded not guilty in Clay County court on Monday.