The Department of Homeland Security is systematically reviewing thousands of pending immigration cases and moving to dismiss those filed against suspected illegal immigrants who have no serious criminal records, according to several sources familiar with the efforts. Culling the immigration court system dockets of noncriminals started in earnest in Houston about a month ago and has stunned local immigration attorneys, who have reported coming to court anticipating clients' deportations only to learn that the government was dismissing their cases. Richard Rocha, an Immigration and Customs Enforcement spokesman, said Tuesday that the review is part of the agency's broader, nationwide strategy...