Pedro Pablo-Solis, 28, a Guatemalan national, pleaded guilty Monday to aggravated identity theft.
Pablo-Solis is the last of five co-defendants to plead guilty in the case.
He helped more than 100 illegal immigrants obtain driver's and non-driver's licenses through the St. Joseph license office during a two-year period starting in 2010.
He was responsible for getting the genuine Social Security card and birth certificates used in the scheme.
Pablo-Solis faces a mandatory two years in prison and a fine up to $250,000 when he is sentenced.