There were two bloody adult shoe prints in the master bedroom but not outside of it. They went back later and actually seized boards from the deck. I think their theory was that the shoes were tossed out of the upstairs window onto the deck below and they hosed off and tossed everything into a trash bag from the kitchen.
And their theory could still be right. The only reason the killer would have avoided using the bathrooms to wash off blood from their hands is if some of it was their own blood.
They really owe it to Michelle and her children to re-run the unknown prints and DNA through national databases.
JMO