Benny tells Sean that a suspect's date of birth does not match his Social Security Number. Unlike the current practice of Enumeration-At-Birth, where the hospital automatically applies for a newborn's S.S.N., hospitals did not do this in the 1970s. At that time people only applied for SSNs when there was an actual need for one, such as applying for a driver's license or for a job the first time. Congress did not enact the Enumeration-At-Birth requirement until the late 1980s, therefore Benny's theory would not have worked.