Volkswagen has apologized and halted the sale of certain diesel cars in the United States following reports it illegally installed software to evade standards for curbing pollution. The Environmental Protection Agency ordered Volkswagen to recall half a million vehicles after finding it installed the devices in a deliberate bid to avoid emissions rules. It remains unclear if Volkswagen officials will face criminal charges. Tyson Slocum of the consumer advocacy group Public Citizen told The Huffington Post, “This is a huge test of how serious the [Obama] administration’s commitment is to prosecuting white collar crime.”