Had the police not shown up, the guy with an airsoft gun would have taken $100-$200 out of a register and ran.
They could have shot him in the street if they wanted. I'm not sure why the police entered the store if they saw him pointing a gun at people.
There are snapshots of the guy from the store video here. I could see this as a justifiable shooting, but charging into the store seemed like it needlessly endangered the people inside.
http://www.ketv.com/news
Banks don't have armed guards and hand over the money so robbers leave without hurting anyone.