who complied with the investigation were subject to harassment and intimidation from their supervisors. The DCAA responded on July 25 that it had asked the US Department of Defense's (DoD) Inspector General (IG) office to investigate the GAO's claims. "We take the GAO report very seriously," said April Stephenson, DCAA's director. US Senator Claire McCaskill said GAO may have uncovered the "biggest auditing scandal in the history of this town," and asked the DoD to immediately fire the supervisors cited in the report. An Associated Press report on November 10, 2008, revealed that DCAA challenged $4.6 billion, or only 1.2 percent, of the contracts it audited as lacking necessary documentation. The agency has not used its subpoena authority in over 20 years to produce the required paperwork from defense contractors under audit. According to the Associated Press, in contrast to the GAO, which saves taxpayers $94 for every dollar it spends, DCAA's return on investment is only $7. As an example, the Associated Press reported that a May 2008 audit of Bechtel Group, supervised by DCAA regional director Christopher Andrezze, showed a "chronic failure" by Bechtel to produce the required documentation for the audit. In spite of this, DCAA issued a report rating Bechtel's internal accounting procedures as "adequate," a passing grade which meant DoD auditors could ease up on the company. The DCAA report did not mention the company's failure to produce the required documentation. A Government Accountability Office (GAO) report in September 2009 found that agency auditors failed to follow "basic auditing standards" in 65 of 69 audits. In its report, the GAO noted that the agency lacks sufficient independence from the contractors and the DoD agencies doing business with those contractors. The GAO concluded that pressure from outside groups creates a hostile work environment in which audit reports are falsified to appease contractors. In response to the GAO report, Senator Joe Lieberman said, "Perhaps it's time for us to consider separating DCAA from the Department of Defense and … making it an independent auditing agency." The DoD IG released a report of its investigation into the agency on August 31, 2009. It found that the DCAA has an "environment not conducive to performing quality audits." An audit of Boeing was cited in which the company was allowed to keep $217 million in taxpayer's money, because a DCAA regional auditor did not perform his/her duties properly. When Boeing