Check-washing is on the rise in the area.
Mail-snatchers erase the ink on checks and rewrite them to steal money.
One woman was busted in Atascosa County accused of running a clever mail theft operation.
Lethema Dawn Cleveland was arrested in late April, and since then the claims against her has grown into a federal case.
Authorities say the 36-year-old stole envelopes out of mail boxes in Atascosa County and in Bexar County.
Cleveland faces numerous charges, and there could be up to more than 150 victims.
Atascosa County deputies say they saw Cleveland in action and pulled her over. They reportedly found fake driver licenses in her vehicle.
Investigators were led to a storage unit in Pleasanton full of computers, printers, company checks and other items used in a check-washing scam.
U.S. Postal inspectors are investigating and the United States Attorney General's Office is reviewing the case.
Authorities say there is a second suspect, but they aren't ready to share that information yet.
Members of the public that believe they are victims of mail theft should report the matter to the U.S. Postal Inspection Service at 1-877-876-2455.