The big picture: Sweeney's already a sled hockey gold medalist — he played a pivotal role in Team USA's victory in the 2014 Sochi Games — and now has his eye on biathlon and cross-country medals.
The latest: Sweeney placed fifth in two biathlon events over the weekend.
He is expected to compete again later this week.
Catch up quick: Sweeney joined the U.S. Marine Corps after graduating from Ironwood High School in Phoenix.
He stepped on an improvised explosive device while deployed in Afghanistan in 2009 and required a bilateral above-knee amputation.
He was awarded a Purple Heart for his service and sacrifice.
The intrigue: Sweeney's using his training as a Scout Sniper to excel in the biathlon event, which combines cross-country skiing and precision rifle shooting, according to Team USA's website.