Calling the phone number gets nothing, not even an answering machine. This looks like a job for --
Hint 3
-- the police department, which is currently on your side. Ask Officer Palmer to look up the number, and he says it belongs to the Grace Church. Hmm.
Hint 4
Father Ullman, the priest at Grace Church, is trying to be completely unhelpful --
Hint 5
-- but he's also quite careless, and eventually he lets slip the name Michael Cooper. Aha! Search for that name on Rosa's phone to find out more.
Hint 6
Once you know that Michael Cooper was also a priest, browbeat poor Father Ullman again. Eventually -- and I would really hate to have this man carry MY secrets -- he tells you that you can find Michael in the school that's part of the church, which will now be on the map.
Hint 7
Oh, and before you go in to see Michael, you might want to save your game; Michael has a great deal to say, all of it pivotal, and you may want to replay the scene if you miss something.