A Florence attorney has pleaded guilty to defrauding his clients. U.S. Attorney Bill Nettles said Friday that 48-year-old William J. Rivers pleaded guilty to mail fraud.

Authorities began investigating after some of Rivers' clients complained to the South Carolina Bar Association. Between 2006 and 2012, prosecutors say more than 100 of his firms' clients were defrauded of more than $3.3 million.

Authorities say Rivers settled personal injury cases but didn't tell his clients or medical providers about the settlement money, which he kept. Prosecutors say that action left Rivers' clients still owing money for treatments they had received.

Prosecutors say Rivers' law partner committed suicide during the investigation. Rivers faces up to 20 years in prison and a fine of $250,000 when he's sentenced.