Immigrants’ possessions are still strewn around this former stash house, from toothbrushes to playing cards to clothes. It is becoming more common for smugglers to hold migrants captive for days as they seek to extort more money out of their relatives or friends, law enforcement officers say. Ilana Panich-Linsman for The Wall Street Journal
SAN JUAN, Texas—Sgt. Rolando Garcia sat in a surveillance van earlier this month, staking out a white wooden house surrounded by sprawling cactus in this city of 35,000 residents near the U.S.-Mexico border.
He wasn’t looking for signs of drugs or weapons, but for evidence that it was a stash house packed with illegal immigrants, the hottest illicit commodity for smugglers on the Texas border.
Human smuggling is nothing new along the U.S.-Mexico boundary, but federal, state and local officials report a rise in Texas in recent months, as thousands of Central Americans sneak into the country—including many unaccompanied children. The migrants are overwhelming authorities along the Rio Grande.
The criminal networks being uncovered in Texas involve large groups of immigrants—and increasingly brazen smugglers. They often hold migrants hostage and threaten them with brutality if their friends or relatives don’t produce extra money to release them, authorities said. Sometime, they kidnap migrants from rival smuggling gangs.
Earlier this month, San Juan police found 43 people trapped inside one suspected stash house. The migrants claimed that their captors threatened to electrocute them if they tried to escape, according to a criminal complaint filed in federal court.
“We don’t enforce immigration law, but we’re obligated to intervene,” said Sgt. Garcia, who said his department is now getting five to six calls a day about suspected stash houses. It has busted 21 such houses in the past nine months, four more than in the previous 12 months.
“The president of the United States has to openly say, ‘If you come here and you enter this country illegally you’re going to go back,'” Mr. McCain said at a Wall Street Journal breakfast gathering in Washington. “That is not the message that’s being put out on television and radio in Honduras, El Salvador and Guatemala.”
The rise in smuggling and related violence in Texas hasn’t reached the proportions that plagued Arizona last decade, when that region was the hot spot for illegal immigrant traffic into the U.S., but authorities say they are concerned that it is worsening.
“We are hoping that we don’t find ourselves in the same place as Arizona did,” said Janice Ayala, a special agent in charge with Homeland Security Investigations, part of U.S. Immigration and Customs Enforcement.
Smuggling is becoming a threat to public safety in Texas, some local law-enforcement officials say. They report a rise in high-speed pursuits by authorities as more immigrant-laden vehicles pass through the area, and an increase in car thefts as smugglers seek vehicles to transport the migrants.
Last week, Texas Gov. Rick Perry and state legislative leaders authorized $1.3 million in extra funding a week for the rest of 2014 to allow the Texas Department of Public Safety to mount a counterattack to the jump in illegal immigration, arguing that federal officials were failing in their duty to secure the border.
“Texas can’t afford to wait for Washington to act on this crisis and we will not sit idly by while the safety and security of our citizens are threatened,” Mr. Perry said in a statement.
The U.S. Border Patrol didn’t respond to requests for comment for this article, or provide regional statistics on stash- house busts. But according to recent Texas Department of Public Safety reports seen by The Wall Street Journal, there were approximately 17 stash-house busts in the region between May 7 and June 4, resulting in the apprehension of more than 400 immigrants.
“At the end of the day we can’t allow the crimes that are being committed, so we have to do something,” said Steve McCraw, the head of the Texas Department of Public Safety.
Recently, some migrants have been turning themselves in to authorities shortly after they cross the river, mindful that they likely would be released pending deportation proceedings due to a shortage of detention space in Texas. But many continue to pay to be smuggled past the river to cities such as Houston and Dallas, law-enforcement officials say.
The demand for stash-house space, which smugglers usually rent, has grown so much that authorities recently discovered an outdoor encampment of makeshift huts in the outskirts of McAllen, Texas, near the border.
It can be a lucrative business. Smuggling fees range from $3,000 to $5,000 a person for Central Americans, and can go above $10,000 for migrants coming from places farther away such as China.
Two brothers were recently sentenced to more than 30 years in prison after pleading guilty to kidnapping immigrants from a stash house to extort them. Ms. Ayala of Homeland Security Investigations said it took almost a year to wrap up that case, adding that others that go to trial can take much longer.
The cases can involve dozens of witnesses that investigators have to interview, said Ms. Ayala. They ultimately have to be prosecuted by a U.S. attorney’s office, which also has limited resources to handle the work.
It requires “a lot of tenacity for our investigators to pursue these cases and ultimately get people apprehended and charged for their participation,” she said.
—Reid Epstein contributed to this article.