A European case? American guy in Germany, last seen unconcious on the ground in downtown Frankfurt. Tracking dogs followed his scent to the river where his shoe was found.
http://www.azcentral.com/news/articles/2009/12/18/20091218studentmissing1218.html
http://www.azcentral.com/news/articles/2009/12/18/20091218studentmissing1218.html