Per the team:

The Washington Capitals have acquired left wing D.J. King from the St. Louis Blues in exchange for prospect Stefan Della Rovere, vice president and general manager George McPhee announced today.

King, 26, is a 6’3", 230-pound veteran of 101 NHL games. The Meadow Lake, Saskatchewan, native has posted nine points (four goals, five assists) and 185 penalty minutes in his time with the Blues. He played 12 games in St. Louis and 10 games for Peoria of the American Hockey League (AHL) in 2009-10, seeing limited time due to a broken finger. He is under contract through the 2011-12 season.