FBI Investigating Multi-Billion-Dollar Defense Contractor With Tax-Exempt Status In Congressman's HometownCBS News has learned the FBI is investigating a little-known not-for-profit organization called Commonwealth Research Institute. It's located, like a lot of Rep. John Murtha's, D-Penn., pet projects, in his hometown, Johnstown, Penn. Commonwealth gets the same benefits as the Salvation Army or any other charity: It doesn't have to pay taxes. But its line of work may be surprising. It's a defense contractor. "It certainly raises a question," says Dean Zerbe, a former top Senate investigator. He questions Commonwealth's tax exempt status, saying it seems to do business just...