The nomination of a former prosecutor to become secretary of homeland security could reopen questions about his response to allegations of wrongdoing by a longtime government informant and reputed organized-crime associate. The claim that the nominee, Michael Chertoff, failed to rein in the informant, Stanley Myatt, was first raised in May 2003 when the ex-prosecutor was up for confirmation to the federal bench. A dispute over how to pursue the assertions, made by a conservative legal watchdog group, Judicial Watch, led six Democrats to vote "present" on the nomination in the committee. According to Judicial Watch, Myatt worked as an...