How did they find her home? I would think that with the threats made against her, she had U.S. Marshals Service protection. From U.S. Marshals Service website:
Protection of federal judicial officials, which includes judges, attorneys and jurors, holds a high priority with the Marshals Service.
http://www.usmarshals.gov/duties/index.html
She might have had bodyguards but this happened when she was not at home, a vicious thing.
A federal judge's wife was raped by a guy he had put away got out of prison. In Baltimore. The entire family had bodyguards for years after that as I remember. he threatened to come back and kill her if I remember.
If so then maybe other U.S. Marshals in the house were able to provide protection. Or maybe not.
I don't think all federal judges necessarily have protection. It's probably case by case. The judge who presided over the 93 WTC bombers has constant protection.