Stanford isn’t the only major research university that failed to detect an impostor making free use of its campus, The Hartford Courant reported. The newspaper quoted police investigators who say a man posing as a law professor at Yale University conned undocumented workers from Ireland into thinking he could help them get a green card — for a $5,000 fee. Investigators say the man met with some of his victims in an office at the law school, and received checks from others at a university address. As they attempt to locate hundreds of potential victims, the investigators are also trying to sort out how the man secured office space in one of the most prestigious law schools in the country, as well as a school identification card and e-mail address. —Charles Huckabee