Transcript for Samaritan Saves Trooper Shot in Alleged Ambush Attack
It's melting wax. First we'll talk about the man they are calling heroes for swooping in to save a police officer in distress. One used his own gun to kill the suspect who was tussling with the wounded officer following what authorities are calling an ambush attack and ABC's Neal Karlinsky has all the details from our Los Angeles bureau. Hi, Neal. Reporter: Paula, Dan, good morning. Just imagine driving down a dark highway and seeing a man attacking a state trooper. Most might call 911 but wouldn't pull over and get out. Two motorists did risking their own lives to help in this case. Officer down, officer down. Reporter: Professional as it sounds that voice isn't a police officer but one of two random motorists Arizona police are calling heroes this morning for saving the life of state trooper Ed Anderson. This is a civilian. 'Shot on I-10. He's in real bad shape. Please send air support, helicopter please. Reporter: It was after 4:00 A.M. Thursday in a rural area along Arizona's I-10 when trooper Anderson came upon a rollover crash while responding to a call of shots fired. While he was putting flares down in the road police say he was ambushed and shot at least once. The suspect then got on top of him and started beating him. That's when the first of two motorists pulled over to see what was happening. The trooper says, please help me and asked the uninvolved third party for help. Reporter: Police say that unidentified motorist ran back to his car, got his own gun and told the man attacking trooper Anderson to stop. The suspect refuses, the uninvolved third party fires striking and killing the suspect. Reporter: It was yet another innocent passer-by who grabbed the police radio and called in for help. Yeah, the gentleman was shos by the passerby who stopped the altercation after the officer was shot. Reporter: The unidentified suspect was killed. A second person, a woman was also found dead at the scene after apparently being ejected in a crash. Investigators say Anderson, a 27-year veteran, is lucky to be alive. Trooper Anderson has undergone surgery and is doing well this morning according to police. The motorist who shot that suspect dead will not face any charges. Paula, Dan. A wild story, Neal, thank you very much.
This transcript has been automatically generated and may not be 100% accurate.