Found this on WaMu - apparently Deanwood and Suitland stations are the "winners".
http://wamu.org/news/11/09/22/wmata_top_10_worst_stations_for_crime
Just for kicks, I wanted to see how this broke down by service. It went this way:
Red: 3
Green: 10
Orange: 6
Blue: 6
Yellow: 4
To arrive at these numbers, each staton got one mark per line served. Thus New Carrollton was marked once for Orange, while L'Enfant Plaza was marked four times, one each for Blue, Orange, Green, and Yellow. The result doesn't really surprise me, though.