Hiya!

Just before i start, i just wanted to say there is and will always only be one Martin Riggs to me and that is the original played by Mel Gibson. I have only watched the movies- never bothered with the tv show.

The following sketches were to practice speed drawing and not using an eraser. I used 3 different shades of brown pencil (3 pencils only). 

These were all drawn from parts of Lethal Weapon 1. Not many ended up looking like him but practice is practice and i hope one day i'll be able to get it first go :). 
Top Left, and bottom middle look like Riggs the most to me, but my favourite is the one on the bottom left there :).

Enjoy!!