>> it was so fast. as soon as i saw him draw the gun the way he did, it was just instant reaction. >> drop the gun! [ gunshots ] >> shots fired. >> he eventually dropped to his knees. we tried to direct him to throw the gun away so we could approach him. >> drop the gun! >> he's still got the gun, dean. >> drop the gun! >> the suspect was still armed. >> you okay? he was still moving. and he still had the gun pointed down towards officer mcginniss. >> the gunman is down, but he isn't dead. and as day turns to dusk, backup arrives and disarms him. he dies shortly after on scene. >> he had a blood alcohol of 18. that's roughly double what would be legal in missouri. and had marijuana in his system. >> investigators later learn the