>> with turner just a few seconds behind him, mcginniss cuts across the grass to get a good look at the man, dash cam rolling the whole time. by now, officer turner is on the scene. >> i really expected him to take off running, we'd be in a foot chase. >> as mcginniss pulls up closer, the man turns around. that's when, without warning, the situation turns ugly. >> as i went to hit my sirens, i saw him lift a gun up and point it at his face. >> drop the gun! >> so i ducked down and took an evasive action to get away. and bumped into the car door and fell to the ground. >> he wasn't being elusive any more. he was actually in attack mode. he was going to execute officer mcginniss. he had no intention on running away. >> as the gunman closes in on mcginniss, officer turner races in, opening fire. >> it was so fast.