One day after being placed as the 500th fugitive on the FBI's Ten Most Wanted List, 64-year-old Walter Lee Williams was arrested around 8:30 p.m. Tuesday in the southern resort city of Playa del Carmen while having a cup of coffee.
The FBI on Wednesday said a tip from a Mexican citizen led to Williams' arrest.
"A citizen saw his photograph in the local media in Mexico, recognized him, contacted Mexican law enforcement authorities and they ultimately got with the FBI and coordinated an arrest," said Bill Lewis with the FBI.
Williams was wanted on charges of sexual exploitation of children and traveling abroad for the purpose of engaging in sexual acts with children. According to the FBI, Williams has an extensive history of travel throughout the South East Asia region, specifically the Philippines.
Williams allegedly traveled from Los Angeles to the Philippines in January 2011 to engage in sex acts with two 14-year-old boys he met online in 2010, officials said.
The investigation started in February 2011 at Los Angeles International Airport when Williams returned and his personal computer was taken and investigated. Nothing was found in the initial search and interview. Authorities said Williams then fled the country.
Prosecutor Gaspar Armando Garcia Torres said it wasn't clear how long Williams had been living in Playa del Carmen and that the fugitive also had an address in nearby Cancun.
The person who turned Williams in could be eligible for the $100,000 reward offered in the case. Williams taught history, anthropology and gender studies at USC until 2011. Los Angeles police said no illegal activity connected to Williams ever occurred on the campus of USC.
Williams is due in court on Thursday.
The Associated Press contributed to this report.