"Lehigh University has placed Devlin on administrative leave and is cooperating fully with law enforcement," the university said in a statement.
Authorities said Devlin, who used the screen name Phillyguy5, began an AOL relationship in May with a female county detective posing as a 32-year-old woman with two daughters ages 7 and 9.
According to the criminal complaint, Devlin instant-messaged that he and his wife grew up in an "open-minded" lifestyle and began "preparing" their own two daughters when they were 10 and 12 years old. He asked the detective if she was "teaching her daughters how to be bisexual," the complaint said.
When the detective responded that she had been "busy with work," Devlin suggested that "we should try to find a way to do more than chat online," the complaint said, suggesting they "set a date to party."
"Meeting other families like ours is always risky . . . but it is also so exciting," the complaint said he wrote.
Devlin detailed explicit sexual activity that would occur if they met, the complaint said, adding that Devlin had similar sexual communications with another female detective posing online as the mother of two daughters ages 11 and 14.
The complaint said Devlin arranged to meet the first detective and her daughters in the Kohl's store parking lot in Morton on Tuesday evening. "We need to trust each other, but I read about guys trapped by cops every day," Devlin allegedly wrote.
After getting out of his black Lexus, Devlin was taken into custody by county detectives, who were assisted by the Morton and Springfield Police Departments, the complaint said.
Devlin began working at Lehigh in March 2003, the university said. Before that, he worked for nine years at the University of Pennsylvania in positions ranging from director of the Boettner Center of Financial Gerontology in the School of Social Work and the associate director of institutional research.
In a news release, Delaware County District Attorney G. Michael Green said the Internet Crimes Against Children task force has been responsible for nearly 350 convictions since it began operating in Delaware County in August 2002.
Green, who has repeatedly stressed the dangers of "online predators," said Devlin's arrest marks the culmination of two similar Internet stings in the last two weeks. On June 26, Michael David Tedesco, 34, of Williamstown, was charged with offering to pay a detective posing as a mother for sex with her two daughters.
Contact staff writer Kathleen Brady Shea at 610-701-7625 or firstname.lastname@example.org.