A 13-year-old illegal immigrant who fled to his native Mexico amid a sex scandal with his schoolteacher could be eligible to return to the United States under a new visa the government started granting the week before he disappeared.

The visa helps illegal immigrants who are victims of sex crimes. If the boy, who spent most of his life in Lexington, Neb., qualifies, he could stay legally in the United States for four years and eventually apply for permanent residency. It also would 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 and middle school teacher Kelsey Peterson were found in a mall parking lot in the border town of Mexicali, Mexico, 1,500 miles from where the pair 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.

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.

Cabrera said a conviction would not be necessary for the boy to qualify for the visa.

"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 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 delayed issuing the visas until this year.