Originally a third-round draft choice of the Seahawks in 2002, Richard has played mostly special teams in the NFL.
Richard was a very productive player at USC with eight career interceptions, including three returned for touchdowns.
The acquisition of Richard follows the signings of offensive linemen Alonzo Ephraim and Frank Middleton the last two days.
Richard joins a cornerback corps in need of quality depth behind starter Sam Madison. Besides Madison and Richard, the other cornerbacks on the roster are rookie Travis Daniels, Reggie Howard, Mario Edwards and Alphonso Roundtree, along with injured players Will Poole and Shirdonya Mitchell.
Poole and Mitchell both are expected to miss most, if not all, of the season because of knee injuries.
As for Flemons, he's a young player who bounced on and off the Dolphins roster several times last year. He showed some pass-rushing ability in the preseason last year, but found himself fighting an uphill battle given the talent the Dolphins have accumulated at defensive end.