From the SSX Tricky bio:
Marty is Mac's older ex-patriot cousin. His family moved to Germany from the US in the early 80s, but still spend the holidays with family back in the states. It was during a winter vacation that Mac turned Marty on to snowboarding, and eventually the SSX World Circuit. In the off-season Marty runs an underground hip-hop club with some friends in Munich, where he doubles as a DJ. Marty is obsessed with all the adrenaline sports, especially winter sports, with snowboarding and sledding topping his list. Marty is open and easy-going, but when competing he is a perfectionist, much like his younger cousin, Mac. He does have a bit of a temper, and when pushed may become slightly unhinged.