The 49ers signed defensive back Craig Dahl to a three-year contract Saturday, finding an apparent replacement after Dashon Goldson received a five-year deal from the Buccaneers last week. Dahl, 27, spent the past four seasons with the Rams and registered 78 tackles and an interception in 2012. "It's a program I'm really familiar with, players and coaches I'm familiar with how they operate and the basis of what their team fundamentals are," he said.