For Johnson, whose career started with the Bears and most recently continued with the Cowboys, he will get a chance to go back to a more natural position along the defensive line. Johnson will play the "three-technique'' for the Bengals, giving him the chance to do some pass rush and shoot the gaps to make plays. The Cowboys tried to make him a nose tackle in their 3-4 defense the past couple of years.
His agent, Jerrold Colton, told The Associated Press the Bengals' defensive scheme is a better fit for Johnson than his previous team, the Dallas Cowboys.
The 27-year-old free agent had 33 tackles and three sacks in two seasons with the Cowboys. He was suspended the first eight games of the 2008 season after a series of legal troubles when he was with the Bears.
The 27-year-old Johnson was a second-round choice of the Bears in 2004. He started 15 games in three seasons for the Bears. The Bears released him after his eight-game suspension for a gun violation. The Cowboys picked him up and developed him into a nose tackle over the past two seasons.
Johnson was released by the Bears in June 2007, days after he was pulled over by police in Gilbert, Ariz., for speeding. There were never any charges in the Arizona case, but Johnson had already served a two-month jail term for violating probation from an earlier gun charge when he had unregistered firearms in his home.
While with the Bears, he helped them win the 2006 NFC title before they lost to Indianapolis in the Super Bowl.
Johnson had no off-field problems with Dallas.
One of the appealing aspects of signing with the Bengals was a chance to work with former Cowboys coach Mike Zimmer, who is in his second season as the Bengals' defensive coordinator. He runs an aggressive 4-3 defense that fits Johnson's style.
The Bengals have a history of giving second chances -- and third and fourth chances -- to players who get into trouble. Linebacker Odell Thurman and receiver Chris Henry were the most high-profile examples, piling up the arrests and suspensions.
In all, the Bengals had a run of 10 player arrests in a 14-month span.
John Clayton is a senior NFL writer for ESPN.com. Information from The Associated Press was used in this report.