I used to work with Marshall at Cartoon Network. He's funny, passionate and loves people, qualities which manage to find their way into his caricatures.
Marshall did caricatures like these in the 80s and early 90s when professional computer caricature was still somewhat uncommon. I think he had to resort to added photographic and prismacolor enhancement to get what he was looking for.
What a shame that newspapers didn't pick up on what Marshall did...They could have had a Sunday comedy section built around funny pictures like these! As it happened Mad magazine picked up Marshall so it all had a happy ending!