The Homeland Security Department is systematically reviewing thousands of pending immigration cases and moving to dismiss those filed against illegal-immigration suspects 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 about a month ago and has stunned some immigration attorneys in Texas, who've reported coming to court anticipating clients' deportations only to learn the government was dismissing their cases.

Richard Rocha, an Immigration and Customs Enforcement spokesman, said Tuesday the review is part of the agency's broader, nationwide strategy to prioritize the deportations of illegal immigrants who pose a threat to national security and public safety.

"Our agency focuses our limited resources on criminal aliens and those who are considered national security and public safety threats," Rocha said.

Critics assailed the plan as another sign that the Obama administration is trying to create a kind of backdoor "amnesty" program.