I agree with the last post. In 2014, there are
many simple weapons an officer or guard(or any citizen concerned with low profile defense items) can apply quickly or in a critical incident.
Everything from stun guns/EDWs on smart-phone cases to defense pens/ink pens to lightweight concealed ASP batons.
I like the newer lightweight polymer impact weapon from Mako Defense Group. It includes a glass breaker tip for emergencies.
Taser C2 models have a
longer charge than the regular LE models & run about $300.00 USD.
Pepper sprays or OCs like Zarc's Vexor(my choice) or Sabre Green aren't perfect but as noted, can be easy to carry & "street legal".
One newer weapon not yet on the US market is the cool "Dazer Laser",
www.laserenergetics.com . It puts out a bright green laser distractor that disables a subject briefly. It's only available to spec ops, sworn law enforcement & public agencies in 2014, but they might R&D a good model for the general public(private security). If I can recall the company website, I'll post it here.
I read about this new weapon in the latest
Rogue Warrior novel by retired SEAL officer, Richard Marcinko;
www.DickMarcinko.com .
I'd add that a well made LE/professional grade white-light should be a duty gear item for any serious armed professional. New styles & upgrades are common. 5.11, Streamlight, Fenix, Surefire all have good kit that could help you.