TODAY | October 04, 2013
>>> on police shoot out on an oregon highway . it left a father of three dead and officer injured. we should warn you the video is disturbing. miguel almaguer has the story.
>> reporter: it started as a routine traffic stop outside portland oregon .
>> please get back in the car for me.
>> reporter: but in seconds.
>> sir, get back in the car for me.
>> the exchange became deadly. he opened fire on a state trooper for no apparent reason.
>> there were words exchanged there on the side of the freeway but it happened very quickly.
>> reporter: dressed in fatigues said to be in the army allen appears to empty his clip. the state trooper , who survived, was amazingly just shot once. allen took a bullet to the chest but stayed on his feet.
>> 5326 shots fired. i've been hit in the side. i'm okay. suspect left.
>> reporter: allen was found slumped over in his car a half mile away. also in the vehicle, allen 's three children, 10, 13, and 15 that were not injured.
>> it's upsetting because he was trying to take his children on a road trip .
>> reporter: the case into the dramatic shooting is now closed but what triggered the gunman may never be known. for today, miguel almaguer, nbc news, los