Security cameras are no good unless they capture a good face shot. Placement is critical. When combined with a properly installed security alarm, they can capture video of a smash and grab, but not prevent all attacks.
I've been installing alarms and cameras for 16 years, some people are just willing to attempt a break-in no matter what. The alarm makes them leave sooner with less theft, the cameras capture them doing it, but neither one will stop all attempts. Bullet proof glass should be installed for maximum results, but is very expensive.