reporter: mike brawn retired in 2008 as chief of operations for the drug enforcement administration. he says al kassar is suspected of working with terrorists and rogues around the world. his name is also propped up in a litny of international scandal. iran contra in the u.s., armed embargo cases in u.s. and a terrorist attack in argentina. tonight, the inside story of how american law enforcement set an international trap to finally bring to justice someone they describe as a major force for evil. without guys like him, these other very powerful global threats will have a very tough time carrying out their operations. this was an intricate, expensive and dangerous sting operation, thomas. dea agents actually posed as terrorists from the from the co