In February 2006, with roadside bombs killing more and more American soldiers in Iraq, the Pentagon created an agency to defeat the deadly threat and tasked a retired four-star general to run it.

Five years later, the agency has ballooned into a 1,900-employee behemoth and has spent nearly $17 billion on hundreds of initiatives. Yet the technologies it's developed have failed to significantly improve U.S. soldiers' ability to detect unexploded roadside bombs and have never been able to find them at long distances. Indeed, the best detectors remain the low-tech methods: trained dogs, local handlers and soldiers themselves.

A review by the Center for Public Integrity and McClatchy of government reports and interviews with auditors, investigators and congressional staffers show that the agency — the Joint Improvised Explosive Device Defeat Organization — also violated its own accounting rules and hasn't properly evaluated its initiatives to keep mistakes from being repeated.

Meanwhile, roadside bombs remain the single worst killer of soldiers as more U.S. forces have been transferred out of Iraq and into Afghanistan. Known in military parlance as improvised explosive devices, the crude, often-homemade bombs killed 368 coalition troops in Afghanistan last year, by far the highest annual total since 2001, when the U.S.-led war there began, according to icasualties.org, which tracks military casualties in the Afghanistan and Iraq wars.