Law enforcement authorities located a 25-year-old sixth-grade math teacher and basketball coach overnight Friday, whom they suspected had run off with 13-year-old former student of hers.
Kelsey Peterson remained in police custody Saturday morning, while the eighth-grader with her was in protective custody in Mexico.
Police believe the the pair crossed over to Mexico together from a Californian border Tuesday, after disappearing earlier this week when local police began investigation whether they had an intimate relationship.
The student had last been seen on Oct. 26, according to the Associated Press.
Court documents reportedly revealed affectionate e-mails and love letters between Preston, who taught at Lexington Middle School in Nebraska before she was put on administrative leave a day before she vanished, and her student.
A judge issued an arrest warrant Monday for Peterson, but school officials said they had seen no troubling signs prior to the incident.
"There was no prior indication that we should be concerned," said district superintendent Todd Chessmore.
But the student's family members disagreed and said not only did they tried to end the couple's relationship, but they also attempted to warn others about the relationship between the two, which they said began last year.
"We were trying to let everybody know what was going on here," said the student's aunt, Laura Rodriguez.
"He would always be at her house," added the boy's cousin, Jessica Vera. "They would always be together."
Now, Peterson faces several charges including kidnapping, child abuse and contributing to the delinquency of a minor, according to the AP.