Entering London, Sehn was coming off a first place finish in the 10m event at the 2012 Winter Senior National Championships where he also won gold in the 10m synchro with Kevin Geyson.
At the 2011 Pan American Games, Sehn and Geyson captured bronze in the 10m synchro. The duo would also reach the final at the FINA World Championships in the same event. At the Summer Senior National Championships, Sehn won gold in the 10m and in the 10m synchro with Geyson.
In 2010, Sehn competed at the Commonwealth Games and finished third with Geyson in the 10m synchro.
From 2004 to 2010, Sehn won 10 medals at the Summer Senior National Championships including six gold, one silver and three bronze. He won eight medals at the Winter Senior National Championship in that period of time as well (six silvers and two bronze).
National titles (include event, year):
2011 – Summer Senior National Championship – Gold on 10m & 10m synchro (Geyson)
2010 – Summer Senior National Championship – Gold on 1m & 10m
2009 – Summer Senior National Championship – Gold on 1m & 10m
2007 – Summer Senior National Championships – Gold on 3m
2006 – Summer Senior National Championships – Gold on 1m
World Championship appearances – Best results by year:
2011 – FINA World Championships – 8th on 10m Synchro (Geyson)
2009 – FINA World Champiionships – 7th on 1m