Primary: While you’ll most likely want to do most of your setting up during the day, you’re still going to need to do some work in the dark. I recommend a headlight as your primary light, so you can keep both hands free. Of all the options you have, my favorite is this Fenix Flashlight HP25R Rechargeable Headlamp, because it offers variable output from a low of 4 lumens up to a blazing 1000 lumens, plus a low-output red LED. The red allows you to use it in the dark without affecting your night-adjusted vision, so you can use the white light at any output for setting up and navigating, then switch to the red when it’s time to start your investigation. I also like that the battery compartment is separate from the light head and situated on the back of the strap—this distributes the weight evenly, and the relieves neck strain that can occur when all the weight is forward, pulling your head downward.
Backup: For your backup, I’d go with this other NITECORE, the Chameleon. It has multiple outputs from 1–440 lumens and multiple colored LEDs for night work, but most importantly, it is also outfitted with a powerful 1500mW invisible Infrared (IR) LED. This IR LED will help during your nighttime investigations by providing additional illumination to your camcorder (see below) and allow you to navigate without visible light.