These companies are set up perfectly legally, they carry on normal business activities and pay their employees well. They have checking accounts in the national banking system and with several banks in the United States, enabling them to write checks in Costa Rica that can be debited abroad. There is no control on capital entering the country. This practice was very widely used in 1992-1993. Some company directors were convicted, not of money laundering but of defrauding the state.
Transactions are even easier with foreign off-shore banks domiciled in tax havens.
These banks open subsidiaries in Costa Rica operating under foreign laws and escape any form of administrative or legal oversight. The law on psychotropic substances also obliges prosecutors to prove the relationship between the money in question and drug trafficking. In most cases the mules are not convicted, because prosecutors cannot prove the illegal origin of the money they were carrying. The offence is therefore not failing to make a declaration, but falsifying it.