The priest is still either ignorant or pretending to be, so let's go talk to someone else. Try the doorman at George's apartment.
Hint 2
The doorman says that Lia is a cop. Hmm. Maybe our almost-helpful cop friend can tell us more.
Hint 3
Durkin, however, is only marginally helpful; he confirms that Lia is a cop and her last name is Pierro, but otherwise he's mum. Time for some undercover work.
Hint 4
Switch to Joey and go inside to the back room again. One of these two desks is Lia's.
Hint 5
Right-click on the desk on the right. Among the stuff here, there's a photo of a "cute kid" and an envelope with Lia's home address, which is now on your map.