Debbie Dunn, who made the 2012 U.S. Olympic team in the pool of runners for the 4 x 400-meter relay, tested positive for the likely presence of an anabolic steroid at the 2012 U.S. Olympic trials in Eugene, Ore.

Dunn, 34, of Norfolk, Va., finished fourth in the 400 meters at the trials.  She was the 2010 indoor world champion and outdoor U.S. champion in the event and ran a leg of the gold medal 4 x 400 relays at the 2009 outdoor worlds and 2010 indoor worlds.