You call "Greggy", who you guess is probably the Gregory the "Maleman" from the note, who Lucille Karryoke believed Maureen may have run off with. He answered on the third ring.
GREGGY: Yeah? It's Gregory.
YOU:
This is the police. I'm calling to inform you that Maureen is dead.
OR
Is your refrigerator running?
OR
Hi, it's Maureen.