>> he screams out. >> you hear me yelling out "help, tyler." we call our communications center here at this district office, they're known as tyler. that's their call sign. >> but his cries for help go unheard. he doesn't have a radio on him. and the dashboard camera is recording audio, but it's not being transmitted to anyone. >> so, i actually did not have a body mike on that could transmit to tyler. they can't hear my video or anything else. tyler! tyler! it was an instinctive reaction. no one could hear me unless they just happened to be within earshot of my voice. >> he's in intense pain and bleeding profusely. he struggles back to his patrol car where he can radio for help. >> i was able to reach in and grab the radio and make a call out for help. tyler, help! i've been shot! help, tyler! help, please! >> this time, police were able to hear him and help is on the way.