I'm not a LEO, but I do work for a fairly serious Hospital security team. The area we're in has a lot of mental health and drug issues and we work closely with local law enforcement. I personally carry a PM2 DLC which has been one of my go-to's for the last 3 years or so and a couple other guys carry enduras in combo edge or full serrated and really like them. Most of the local police as well as our Security team are issued pants more like BDU's (Ours are from 5.11 tactical) and they have lots of extra pockets on the legs. Most LEO's and SO's carry their knives in one of these leg pockets, although a few, including myself on occasion, carry in their dominant hand back pocket. Generally having arranged their duty belts to have a small gap, large enough to get your hand in and deploy the knife. A couple of the more old school guys use belt pouches.