I am not involved in this case, but I have experience finding the location of living people in the U.S. using the website known as PrivateEye:
http://www.privateeye.com/?from=p15412&vw=peopleIf the person's name is common, and you know the date of birth, the website will accept input of a d.o.b. in this format: 01-04-1936. The d.o.b. is used to differentiate between people of identical name.
If an exact d.o.b. is input, it will even search without a surname, with or without you input of the name of a state.
Reg Niles