OMAHA, Neb. — The 13-year-old boy who fled to Mexico with a Nebraska schoolteacher could be eligible to return to the United States under a new visa the government started granting the week before he disappeared.

The new visa would let the boy, who was an illegal immigrant in Lexington, Neb., live legally in the United States for four years and eventually apply for permanent residency. It would also extend temporary residency to his parents and his unmarried siblings under 18, if they applied for it.

“It’s a win-win,” U.S. Citizenship and Immigration Services spokeswoman Marilu Cabrera said of the so-called “U” visa. “It helps us and law enforcement be able to solve a crime, and it certainly helps the individual who is a victim of a crime.”

The boy was found in a mall parking lot in Mexicali, Mexico, 1,500 miles from where he and middle school teacher Kelsey Peterson disappeared on Oct. 26. Authorities searched for them for one week.

Peterson, 25, remains in federal custody in El Centro, Calif. A judge denied bail for her Wednesday, and she was expected to be sent back to Nebraska to face federal charges of crossing state lines to have sex with a minor, which is punishable by 10 years to life in prison and a $250,000 fine.

The Associated Press had previously named the boy but later removed his name from stories because the most recent charges allege he was the victim of a sex crime.

Certain crime victims who are illegal immigrants qualify for the visa. Sexual abuse, rape and sexual exploitation are among the crimes covered.

A conviction would not be necessary, Cabrera said.

“It doesn’t matter what the outcome of the case is as long as they cooperate,” she said.

A law enforcement agency, prosecutor or judge in the Peterson case would have to vouch for the boy and say he helped in investigating or prosecuting Peterson in order for the boy to qualify.

The boy told the AP earlier this week that he would be willing to return to the United States to testify against Peterson.

“That’s something that we would have to consider as circumstances came up,” said Joe Stecher, the U.S. attorney for Nebraska. “There are various methods that we could secure his presence here for testimony purposes, and we’ll just deal with the circumstances as they come up.”

Dawson County Attorney Elizabeth Waterman did not immediately return a phone call seeking comment.

The Victims of Trafficking and Violence Protection Act of 2000 established “U” visas to encourage illegal immigrants to report crimes against them. Cabrera said reviews of the rules by the Department of Homeland Security and the Department of Justice caused the long delay in issuing them.

On the Net: U.S. Citizenship and Immigration Services: http://www.uscis.gov