Arizona's law aimed at removing illegal immigrants has grabbed headlines, but quietly this year the number of cities and counties nationwide joining a federal program targeting illegal immigrants convicted of serious crimes has more than doubled.

More than half of Texas counties are now part of the program known as Secure Communities. The program relies on an FBI database and a fingerprint database of anyone who has had contact with federal immigration authorities.

Dallas County was the second county in the nation to sign up for the U.S. Immigration and Customs Enforcement program.

The program targets "the worst of the worst" and has taken criminals off the streets, ICE said.

Critics say Secure Communities spreads racial profiling - an accusation the federal government denies. ICE officials say the use of fingerprints makes the effort colorblind.

The use of Secure Communities has jumped as cities and counties balance conflicting political pressures. Some want to crack down on illegal immigrants. Others want illegal immigrants to report crimes or give witness statements without deportation fears.

The growth of the program comes as Arizona plans to start enforcing its anti-illegal-immigration law Thursday - unless a court intervenes.

Secure Communities seeks those charged with such crimes as murder, rape and drug offenses with a sentence of more than one year. But only 15 percent of those who've been targeted by the program have fallen into what it calls "Level 1" offenses, according to the federal government's criteria and its data in the program's first 18 months of operation.

About 35,000 people were identified nationally as charged or convicted of Level 1 offenses. And nearly 9,000 nationally were deported with Level 1 convictions.

In Dallas County, 886 immigrants were charged or convicted of Level 1 offenses, and 354 with Level 1 convictions were deported.

"We've processed for removal really bad guys that we have taken off the streets to keep the community safe," said Nuria T. Prendes, field office director for ICE's Office of Enforcement and Removal Operations in Dallas.

In a case last August, the Dallas County Jail booked a Guatemala-born man and checked records through the two federal databases. They found he'd been convicted already of aggravated assault with a deadly weapon. He also had previous arrests on drug possession and had been deported. ICE prosecuted him with a fresh criminal charge of re-entry into the U.S.

Checking fingerprints

Under the program, fingerprints at a jail booking are linked simultaneously to a federal criminal history database of the Justice Department and a Homeland Security Department database. The check determines whether an arrested person has ever had contact with immigration officials. The Homeland Security's database now contains more than 100 million fingerprints.

Not all of those identified under Secure Communities are illegal immigrants. The program has identified naturalized citizens and legal permanent residents. Legal residents can be deported if they are charged with some felonies.

Critics say that the link to local law enforcement can allow for racial profiling.

"They overlook that the program operates at the point of booking and arrest," said Sarahi Uribe, an organizer with the National Day Laborer Organizing Network.

A police officer has only to arrest a person, and it can spin into a deportation, Uribe said. The "vast majority" of people picked up have committed minor offenses, she said.

Her organization sued ICE earlier this year to get more information on the program's scope and its arrests.

Secure Communities is marketed as a "kinder, gentler" approach to tougher immigration enforcement, said Stephen Yale-Lower, a Cornell Law School professor of immigration law.

But some critics argue that any fused efforts between local police and federal immigration agents undermine working relationships needed in immigrant communities by making illegal immigrants fearful of reporting crimes or acting as witnesses.

Nearly a fifth of the population in the Dallas-Fort Worth area is foreign-born. In cities such as Dallas, Irving, Carrollton and Plano, it is nearly a quarter or more of the population.

"Everyone's public safety is hurt when trust is replaced by fear," Uribe said.

Secure Communities has helped ICE meet its target of increasing deportations to 400,000 this year, as outlined in a June memo on civil and criminal enforcement.

But that increases the potential for due-process violations under the U.S. Constitution, said Jacki Esposito, policy coordinator for Detention Watch Network, an advocacy group for detained immigrants.

"Secure Communities is a fast track to detention and deportation," she said. "And we have concern about people's due process in an expedited process."

Over the 18-month period ending in April, Secure Communities identified about 24,000 U.S. citizens, according to data supplied by ICE.

ICE officials said most cases are believed to be naturalized immigrants who showed up in the Homeland Security fingerprint database.

Critics of the program say racial and ethnic profiling is a problem, but ICE officials say that doesn't occur at the federal level, because only fingerprints are used in identifying criminal offenders.

"We are not responsible for the local law enforcement agency," said Prendes of ICE. "They do their job. We do our job."

At Dallas County, which operates the nation's seventh-largest jail system, spokeswoman Kim Leach denied profiling problems.

"We don't go through and say, 'You need to flag this person or that person,' " Leach said.

What's different

Secure Communities differs from the ICE's 287(g) program, which takes its name from its placement in federal immigration law. Under that program, selected members of local law enforcement agencies, from jailers to detectives, are trained to enforce certain sections of federal immigration law.

In North Texas, Carrollton and Farmers Branch have 287(g) pacts.

In March, the inspector general of the Department of Homeland Security issued a report criticizing the 287(g) program and calling for additional oversight of such pacts by ICE. It also urged even closer review in areas where there has been a history of racial profiling.

Secure Communities also differs from the ICE's Criminal Alien Program. Both programs target criminal aliens, and both programs are in use in Irving, where a third of the population is foreign-born and several protests, pro and con, were held over tougher enforcement by local police.

Irving Mayor Herbert Gears defended Secure Communities, although he said that the Homeland Security database doesn't identify every immigrant in the U.S. unlawfully.

"It is certainly an appropriate addition to processes in our jail," Gears said. "It falls short of the criminal alien program. If you come in illegally and haven't been in the system, you won't be identified."