2003-04 Trotter competed at the 2003 IAAF World Athletics Championship in France, running in the 400 m, where she qualified for the
semi-finals. That year she also won gold in the 4 × 400 m women's relay, at both the World Championships and the
Pan-American Games. Trotter qualified for the
2004 Summer Olympics team in the 400 m, and was considered a medal contender going into the games. Trotter placed 5th overall in the
400 metres with a personal best time of 50.00s. She was part of the US team which finished first in the
4 × 400 meters relay, which beat the second placed team from Russia by more than one second. Trotter ran first, with a lead leg time of 49.19 seconds.
2005-11 In 2005 and 2006, Trotter repeated as gold medalist at the USA Indoor Championships. In 2007, she won an additional 4 × 400 m gold at that year's World Championships. According to USA Track and Field, "At the 2008 Olympic Trials, in perhaps the most astounding story of the women's 400, Trotter finished third in 50.88. She was running with a broken bone chip in her left leg, the result of an errant car door closing on her two months ago." Trotter is also a multi-time
IAAF Diamond League silver and bronze medalist.
2012 to present Leading into the 2012 Olympics, she again recorded the fastest time that year in the 400 m. She said of the time that, "My personality, demeanor, confidence and spirit were low. That DeeDee is gone. I overcame my entire career crumbling and made the Olympic Team." At the
2012 Olympics in London she won the bronze medal in the 400 meters in a time of 49.72, two one hundredths of a second behind the silver medalist. She was also the lead runner in the gold medal 4 × 400 m US relay team, providing her team with a 10 m lead at the end of her leg. After winning the event, Trotter stated that, "I think the pressure was on to go out and do what we are capable of doing ... I think we finally hit the mark this time. We hit the center of the target. We got it done." Trotter ran her final lap at the 2016 USA Olympic Trials to gracefully retire from the sport. After a thirteen-year career, Trotter waved farewell to the crowd at Hayward Field in Eugene, Oregon, after crossing the finish line of the 400 m semifinals and not advancing to the finals. ==Other work==