Depends on the agency . . . if you're a Postal Inspector, no problem! However, if you're with the FBI, a knife like that would really screw up the "clean cut" image they want all field agents to project. Other agencies, check with your supervisor to ascertain that you won't be violating official or unwritten policy.
Most police chiefs do NOT want their officers carrying automatic knives or oversized fixed blades, as it presents a "poor public image" and it'd be a PR nightmare if you actually hadta use it!
Look into a Spyderco "Civilian" or "Police" folder instead. . .