Assuming this is real, avoid the local pd. Contact your country’s version of the FBI. Tell them you fear for your family’s safety, there have been threats, and that organized crime might be involved. They can use ground penetrating radar to see if there’s potentially any bodies under there before they even dig.
You’re not wrong. Then I just feel bad, because I never finish a book since now I’ve trained myself to fall asleep after two pages no matter what time of day it is.