I’m a patrol officer for the last 23 years, edging ever close to retirement (four more years). I’ll answer questions broadly, can’t give you legal advice, and will only comment on cases/issues/stories in the public domain. Laws & procedures vary in the different agencies and jurisdictions in the US, but as a rule most of it follows the same basic principles.
Yes, I am armed, all police in the US are armed. My basic duty wear is, 9mm Glock 19, two pistol magazines, Taser, Asp, two pair handcuffs, radio, OC spray, small torch, latex gloves. We wear body armour under our uniform shirts. Uniform is a traditional tan uniform shirt with metal badge, black trousers, jacket as required in winter. Hat is a baseball cap.
Our agency is in the process of transitioning to a body camera system, probably implemented later this year/early next year. Our cars all have cameras (front facing) and also record the prisoner cages to include audio.
Our standard patrol vehicle is either the Chevrolet Tahoe, which we are phasing out for the Ford Explorer. They are police package vehicles, heavy duty suspension, beefed up alternator & brakes, prewired for radio/lights/siren, etc. Back seat is a divided prisoner cage with vinyl seats and a barrier between the officer & the prisoners. They vinyl is designed to be easily cleaned and the back floor has a drain hole.
Carried in the car is generally: M-4 patrol rifle (5.56mm), bean bag shotgun, AED, first aid kit, traffic cones, tyre spikes, evidence kits, digital camera, crime scene kits (tape, shoe covers, etc.), small tool kit, breaching tools (crow bar, small sledge hammer), fingerprint kit, water rescue throw rope, various forms, & personal items (rain gear, traffic vests, snacks, water, clipboards, paper, etc.). This all fits in the back in a series of custom drawers & cabinets.
The car comes with a Mobile Data Computer (MDC) (Panasonic Tough Book), electronic ticket writer, fixed multi-band radio, usual lights & sirens, torch charger, map book. The MDC has an integrated Sat Nav function and is linked to our Computer Aided Dispatch. We get all our call information on the MDC, use it to run number plates, driving licenses, ID’s, criminal history and so on. Also has all our report writing software, and links to the e-ticket writer which prints out the ticket issued for offenses. Of course, we still carry a manual ticket book too. Some of our cars have the ANPR system which is linked to the MDC.