Editor’s Note: Second story in a three-part series examining security on U.S. borders.

HARLINGEN, Texas – Several times a day, a chain-link gate rolls open and dozens of illegal immigrants stroll out of the U.S. Border Patrol station here, blinking into the hot Texas sun as they look for taxis to the bus station and a ticket out of town.

Each holds a piece of paper that Spanish-speakers call a “permiso” – permission, courtesy of the U.S. government, to roam the country freely.

Since the Sept. 11, 2001, terrorist attacks, more than 118,000 undocumented migrants who were caught after sneaking over the nation’s borders have walked right out of custody with a permiso in hand.

They were from Honduras, El Salvador, Guatemala, Brazil. But also Afghanistan, Iran, Pakistan, Yemen – among 35 countries of “special interest” because of alleged sponsorship or support of terrorism.

These are the OTM, or “Other Than Mexican,” migrants too far from their homelands to be shipped right back. More than 70,000 have hit U.S. streets just since October.

The Border Patrol is catching them, riding inner tubes across the Rio Grande or trekking through farm fields. But the government has no place to put all the “OTMs” while they await deportation hearings, so they are released with a notice to appear in immigration court.

Many don’t show – disappearing, instead, among the estimated 10 million undocumented migrants living in America.

In the fiscal year ending Sept. 30, 2001, 5,251 non-Mexicans were freed on their own recognizance from Border Patrol custody, according to statistics the agency provided. In fiscal year 2002, that rose to 5,725. Fiscal 2003: 7,972. Fiscal 2004: 34,161.

Last year’s number included at least 91 illegal immigrants from “special-interest” countries.

Releases have soared again this year. With four months left in the fiscal cycle, 70,624 OTMs have been released on their own recognizance – or 70 percent of all non-Mexicans apprehended by the Border Patrol. That includes 50 undocumented migrants from “special-interest” countries, Border Patrol spokesman Salvador Zamora says.

Authorities stress that apprehended illegal immigrants are routinely screened, and any determined to be a risk are detained. Individuals from “special-interest” nations aren’t necessarily more likely to be terrorist threats than others, they note.

Still, front-line officers voice concern that so many who break the law to enter the country are systematically set free.

“I absolutely believe that the next attack we have will come from somebody who has come across the border illegally,” says Eugene Davis, retired deputy chief of the Border Patrol sector in Blaine, Wash. “To me, we have no more border security now than we had prior to September 11. Anybody who believes we’re safer, they’re living in Neverland.”

Outside the Harlingen patrol station, an agent grumbled recently that he’d dislocated his shoulder while catching one group – then, in no time, they walked free.

The afternoon is quickly fading, and 20 illegal immigrants sit under a hackberry tree near the Rio Grande.

“I betcha dollars to doughnuts that there’s a bunch of OTMs in there,” Border Patrol agent Eddie Flores says, swinging his SUV to a stop. He’s right: This group consists of one Honduran, six Brazilians and the rest Costa Ricans, all unfazed at being apprehended by immigration officers. One Brazilian woman smiles, even, then fires off something in Portuguese.

Agent Julio Garcia translates: “They’re depending on me.”

They’re depending on the very system charged with capturing unlawful entrants to help them go free. Nowadays, OTMs often flock to Border Patrol agents rather than fleeing them.

Of the 834,731 apprehensions made by the Border Patrol so far this fiscal year, 100,142 were non-Mexican arrests. That’s a 137 percent increase from the 42,167 non-Mexicans arrested in the year of the Sept. 11 attacks.

Illegal immigrants from Mexico and Canada typically choose to depart voluntarily and can be returned home almost immediately upon being caught. Those from other countries must undergo deportation proceedings and await flights to their nations. A growing number of those are freed with a notice-to-appear because of lack of holding space.

The “catch and release” arrangement happens most frequently in Texas’ Rio Grande Valley, where 91 percent of non-Mexicans caught by Border Patrol agents are then freed, statistics show.