Mexican authorities arrested a University of Southern California professor accused of sex crimes on Tuesday, mere hours after he was added to the FBI’s Most Wanted list.

Walter Lee Williams, 64, was arrested on Tuesday at Playa del Carmen, a Mexican beach resort town, Reuters reports. According to the FBI, Williams worked at USC as a professor of anthropology and gender studies until 2011 and was wanted in the Philippines after allegedly committing sex crimes against children.

Traveling under the guide of conducting “academic research,” Williams allegedly trekked throughout Southeast Asia, including the Philippines, to have sex with underage boys, according to the FBI. During his illicit travels, he reportedly had sex with 10 victims, ranging in age from 9 to 17. He was wanted on charges of sexual exploitation of children and traveling abroad for the purpose of engaging in sexual acts with children.

Prosecutor Armando Garcia told reporters that Williams was captured while drinking coffee at a café. “This person is wanted by the FBI, because he is linked to the sexual exploitation of children,” Garcia said. It is unclear if Williams engaged in any additional sex crimes in Mexico.

Williams has been a wanted man since April, when the FBI issued a federal arrest warrant for the former Palm Springs, Calif., resident, according to the bureau’s official website. The indictment claims that Williams traveled to the Philippines in 2011 to engage in sex acts with a pair of 14-year-old boys he met online the year before, Department of Justice officials said in a statement Monday.

The FBI had added Williams to its “most wanted” list on Monday, Reuters reports. The agency was offering a $100,000 reward for information leading to the capture and arrest of the former USC professor.

"I analyzed the computers and the camera that belong to Williams and found child pornography," Special Agent Jeff Yesensky said in a video posted to the FBI’s website. “He preys on the most vulnerable children.”