The Daily Beast reports that documents in the case against Ghislaine Maxwell indicate the FBI tracked her down because she continued to use her cell phone while hiding in New Hampshire.
Authorities previously obtained a search warrant in New York to receive GPS and historical cell site data for Maxwell’s cellphone account—which had a northeastern Massachusetts area code—within one square mile of her location. But the feds didn’t know the particular New Hampshire building in which she lived.
“The FBI does not know Maxwell’s current location and accordingly requires the information sought in this application in order to locate and arrest Maxwell,” the affidavit states.
The New Hampshire warrant allowed the FBI to “use an investigative device or devices capable of broadcasting signals that will be received by” Maxwell’s phone “or receiving signals from nearby cellular devices,” including Maxwell’s device.”
As The Daily Beast notes, this almost certainly means the FBI used an IMSI-catcher to pinpoint Maxwell’s exact location, and she was arrested just one day after the search warrant was granted.