The Indianapolis Colts signed cornerback Dariuis Butler on Tuesday to bolster their depleted secondary. To clear roster space for Butler, the Colts released offensive lineman Trai Essex, who saw action in the team’s past two games. Defensive backs Vontae Davis (ankle) and Justin King (groin) are slowed by injuries, but with a bye this week, the Colts hope to have the two back in time for their next game against Green Bay. Butler was cut by the Carolina Panthers during training camp. He played two seasons for the New England Patriots but was released before the 2011 season. The 2009 second-round pick has made 14 career starts and played extensively on special teams.