The Olight M20S Warrior is what I point law enforcement personnel toward when they ask me to recommend a light. Most of the lights we stock require two hands to switch between modes, but the M20S can be turned on and off and modes can be switched using just one hand thanks to the dual switches on the tailcap. The rear one turns the light on and off and gives you momentary activation while the side switch switches modes when the light is on and instantly activates strobe when the light is off. This immediate access to strobe is a big reason I recommend the M20S for law enforcement since many officers I speak to like having strobe at the ready for the inevitable ornery drunken guys.
Here is a video if you want to see it: