I use a Princeton Led head light for walking in and out...

For tracking...I want a focusing LED that uses AA or AAA batteries...I don't want it too bright because it can actually wash out the blood that you are looking for...We used to use a Coleman gas lantern because it made the blood glow...A few years ago, I noticed that a LED light could do the same...
After buying and trying several I found this one to be the best for my purposes:

http://www.lowes.com/lowes/lkn?action=productDetail&productId=244292-13229-244292&lpage=none

The reason??? You can focus the beam, this helps tremendously...Too much light, like with a 2-D LED MagLight and you don't see the blood glowing back...