"When the police got the search warrant, they managed to find the private keys" - I wonder where they kept their keys?
  Were the keys in Heather's makeup bag? (ironic)
Just having such possessions and not taking care to make it impossible to find the keys seems a bit silly and weird. I don't side with the criminals, but logically, the first thing the criminals do is go to great lengths to make sure the police can't get their hands on the keys. In another case, it can be assumed that pressure was exerted on them, opening all places where the keys were not hidden.