One of five defendants in a tax fraud case against Mo Money Taxes, the much-maligned and oft-investigated Memphis-based tax preparation company, has pleaded guilty to his role in a conspiracy to file false tax returns in St. Louis. Justin Buford, of Memphis, pled guilty to participating in the case that included tax returns filed during 2010. Buford admitted his role in submitting more than 200 returns that claimed the American Opportunity tax credit. The tax credit is intended to help low and moderate…