A gang of thieves dunked checks swiped from mailboxes into an ink-removing solution, rewrote them and netted $600,000, investigators said.

Dozens of banks and credit unions in south Florida cashed the checks, which ranged from $490 to $24,000. Police said 175 victims lost money in the scam.Twenty of the players were arrested Thursday, including the principals - Luis A. Cossio, 30; Oscar Alarcon, 38; Tania DeLeon, 36; and Rolando Moraleda, 28.

The leaders will be charged with racketeering, conspiracy, forgery and grand theft. If convicted, they could face up to 30 years in prison.

The gang sometimes used children or glue traps for mice to pull envelopes from Postal Service boxes. They also stole from postal trucks and apartment mailboxes, said Mark Grey of the Postal Inspection Service.

Inspectors said the checks were placed in trays with a liquid that removed the payee's name and original dollar amount.

The thieves then paid people to cash the checks. Investigators tracked down the gang through the cashers, who had to show identification to get the money.