It came from people not lawyering up and talking to police. Making false statements is a catch all for any statement made to police regarding anything at all. And the false marriage charges again stem from talking to the police. It is interesting to note the lack of any terrorism charges for these two.This isn't from the suspect iPhone. Too soon and the phone access would be challenged in court.
This came the old fashioned way; good solid investigation - man hours.
What people don't realize is that any statement made to law enforcement about anything that can be shown to be untrue allows them to charge you with making false statements. It does not have to do with what they are investigating. Under pressure of interrogation for hours and days anyone can get some fact wrong. The day you went to a movie, who you visited on what day, what day last week it rained.
Conversely law enforcement can lie, conceal, and say anything to you to get you talking. And they are breaking no law. Saying anything to law enforcement even when innocent will only lead to regrets later. YOU CAN NEVER HELP YOURSELF BY TALKING. YOU WILL HURT YOURSELF BY SAYING ANYTHING, INCLUDING THE TRUTH.