Mint marks were first developed to locate a problem. If a coin was underweight, or overweight, the mint mark would immediately tell where the coin was minted, and the problem could be located and fixed. Another problem which could occur would be a dishonest mint official debasing the coin, or putting less precious metal in the coin than specified. The first mint marks, called "Magistrate Marks" were developed by the Greeks, and named the Magistrate in charge of producing that coin. Debasing a coin, or otherwise tampering with it, was a very serious crime, often punishable by death in many civilizations. For example, in 1649, the directors of the Spanish colonial American Mint at Potosi, in what is today Bolivia, were condemned to death for seriously debasing the coinage. The initials of the assayer as well as the mint mark were immediate identifiers when the coins were inspected.