I slowed the video down on both videos and watched them frame by frame. The first video is inconclusive. The only discernable evidence I could see from that video was the police officer on the left suddenly ducking. The reaction was instinctive and it can only be concluded that the officer felt threatened by something the perp did.
The second video is much clearer as to why the officer felt the need to duck. I'm actually surprised the suspect wasn't shot right there and then. It wasn't until a couple seconds later that the police officers started firing. When they did start shooting, the suspect was walking AWAY.
Unfortunately for us, we don't have any information to would provide us with a context of this situation. IMO, the officers would have been much more justified in shooting this individual when he quickly turned around toward them with his hand and arm raised, holding what they believed to be a gun. However, the fact that he was walking away with his arms down to his sides at the time of the shooting makes this a bad shoot.
A bit understandable? Yes. But a mistake none the less.