Immigration agents assigned to track down people who have ignored deportation orders have increasingly arrested immigrants with criminal records during the past year, new data show.

Data from Immigration and Customs Enforcement show a shift from the prior three years, when more than 70 percent of immigrants arrested by fugitive operations teams had no criminal histories.

About 45 percent of the 35,000 immigrants arrested by the teams during the 2009 fiscal year had criminal convictions. The figure is up from 23 percent during the prior year.

ICE has long claimed it focused on arresting immigrants with criminal convictions who ignored orders from immigration judges to leave the country.

But most people arrested had no criminal histories, which prompted outcries from immigrant rights groups.

ICE director John Morton said earlier this year the agency would focus on finding immigrants with criminal records or who have ignored deportation orders. However, he said other illegal immigrants would be arrested if they were present during the operations,

"The goal is to prevent crime rather than simply to respond to it," ICE spokesman Brandon Alvarez-Montgomery said.

One reason for the change is that agents are working more closely with local law enforcement to develop leads, ICE spokeswoman Virginia Kice said.

Immigrants rights advocates were skeptical of the numbers and wondered whether the data marked a real change in a program they have long criticized as a source of fear in immigrant neighborhoods.

It's unclear whether the Obama administration has shifted the program's focus or whether agents in some regions have just been more successful at finding criminals, said Carl Bergquist, policy advocate for the Coalition for Humane Immigrant Rights of Los Angeles.

"I think the jury is still out," added Paromita Shah, associate director of the National Immigration Project of the National Lawyers Guild.

Earlier this year, Morton also announced the fugitive teams had stopped using arrest quotas.

Mark Krikorian, executive director of the Center for Immigration Studies in Washington, said agents should have discretion about who they arrest, given what he considers the daunting task of finding more than 500,000 immigrants who have evaded deportation orders.

"They've got to start somewhere, and they look for people obviously that have national security issues as well as serious criminals," said Krikorian, whose organization favors stricter limits on immigration.

"As long as they're not sending the message that other illegal aliens will simply be let go, then I don't have a problem with it." he said.