Missing 16-Year-Old Amy Yu May Be in Mexico With 45-Year-Old Kevin Esterly, Authorities Say

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Amy Yu, 16 and Kevin Esterly, 45 have both been missing since March 5. Allentown Police Department

A missing Pennsylvania teen could be in Mexico with a man more than twice her age with whom she may be in a romantic relationship, authorities said.

Sixteen-year-old Amy Yu was last seen on March 5, after her mother dropped her off at a bus stop. School records showed that 45-year-old Kevin Esterly repeatedly signed Amy of school in the months before their disappearance. Police later said that Yu had changed her school documents to say that Esterly was her stepfather.

Mexican authorities issued an Amber Alert and suggested that the pair could be traveling within the country. Authorities believe the teen "is at risk" and is the victim of a crime.

The Allentown Police Department previously issued a warrant for Esterly's arrest that alleged interference in the custody of a child, the Associated Press reported.

In the original missing person notice, Allentown Police said the two might be traveling together in a red, two-door Honda Accord with the PA license plate KLT 0529.

In an interview with WFMZ, Yu's brother said that their family knew Esterly and his family from church. The teen's mother found hundreds of texts between Esterly and Yu on her daughter's cell phone.

Investigators claimed the two had a "secretive relationship" in court documents seen by the Allentown Morning Call.

Esterly was last seen by his wife the morning of March 5. She told authorities that Esterly's personal documents were no longer at the house and $4,000 had been taken from her bank account.

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Allentown Police Department described Yu as a 4'11 Asian female weighing around 90 pounds, while Esterly is a 5'9 white male weighing 185 pounds. In the original missing person notice, police said both "could possibly be endangered."

Missing 16-Year-Old Amy Yu May Be in Mexico With 45-Year-Old Kevin Esterly, Authorities Say | U.S.