We can use Behavioral Recognition, Reporting Processes, Access Control, Employee Awareness, Training, and Physical Layers. Profiling (used in behavioral recognition) can be a very controversial topic, but can it make a difference in the outcomes of situations like these?

For example, the shooter who opened fire in a Las Vegas casino in 2007 walked the strip in a long trench coat in the summer for several hours "looking for someone to shoot." He expected to be confronted but was ignored until he drew his weapon inside the casino...

The methods mentioned above are used in identifying and stopping a shooter, but what can staff take after it has already happened or in the process of happening? What training methods would you provide your staff? What policies/procedures could have prevented the Las Vegas shooting?