The perp may well have been carrying it. He probably used it to break in the back door first.
OK so YOU BELIEVE that this perp scaled a 12ft wall of a house with the security of Fort Knox, and n his underwear, with a hammer in his hand, then smashed in the patio door, SCREAMING where’s Nancy REALLY you believe this OMG!! For crying out loud!!!
So PP did not bring the hammer as theorized in the post I responded to.