In-security Guard?

I'm starting to wonder are security guards really needed in banks?

Recently i heard a news that a bank got robbed. And the security guard was shot. Well it wasn't the first time bank robbery happened.

For goodness sake! What's the use of security guard when robbers are still gonna rob the bank anyway? Might as well don't hire a security and avoid one life being lost.

Or maybe hire more security guards and place them all over the bank. But banks are very conscious of cost. I dunno lah!

Maybe create a ceiling submachine gun and hire a guard to operate it behind closed doors. LoL