Andre Carter (99) sacks David Garrard along with Jeremy Jarmon. (Jonathan Newton / THE WASHINGTON POST)

I am proud to announce that I will be playing for the New England Patriots for the 2011 season. Thanks you for your prayers and support.less than a minute ago via Echofon Favorite Retweet ReplyAndre Carter

Afterward, he added, via Twitter: “Time to hit the books. On to my playbook.”

Carter, 32, had 11 sacks for the Redskins in 2009. A classic 4-3 defensive end, Carter moved to left outside linebacker when the Redskins switched to a 3-4 last year and had 2.5 sacks, starting five games. Carter, who played five seasons for the 49ers and five for the Redskins, hasn’t missed a game since 2004 and had 36 sacks from 2005 through 2009.

The Patriots are on a something of a defensive-line spree. They picked up Shaun Ellis on Sunday and Mark Anderson last week. They join Haynesworth, Vince Wilfork, Mike Wright, Eric Moore, Jermaine Cunningham, Rob Ninkovich and Marques Murrell.