Frank Luke didn't carry his pistol concealed (mandatory WW I content.)
As a former police commissioner and a current reserve deputy sheriff, I can say that almost every cop I know heartily approves of private citizens carrying concealed. I hasten to add that they need to be trained, but I'd much rather have motivated citizens packing than ill trained cops, which is still all too common. No less a city than Portland, OR, stopped annual qualification (forget training) several years ago in order to save money. Long story short: cops killed a 12-year-old boy held hostage. "Bullets are cheaper than lawyers."
The Law Enforcement Alliance of America, composed of active & retired cops, heartily endorses CCW and interstate reciprocal arrangements for retired police and citizens. The chiefs you see on TV with all the starry spangled banners advocating unilateral disarmament are there because they owe their positions to their political masters. The few street cops who favor such things have a saying I've heard a dozen times: "Living in a police state isn't so bad--if you're a policeman."