The house security cameras inside were on.
But you jump right to blaming FBI agents who were doing what the law required. Investigate crimes. And no FBI agent could've "planted" anything because only the stolen boxes were taken out. It isn't some local polices officer planting a baggie of dope then arresting the man for it. Which does happen more than people think. How the previous guy (and you?) could think the FBI planted stolen national security documents so they could turn around and say they found them on the premises....