So, in light of the revelation of having possession of Jayme's phone and actually where they found it, makes the earlier revelation ...
... all the more curious. Law enforcement has Denise's phone. They have Jayme's phone. I expect, but we don't know, that they have James' phone. So, what exactly were they looking for?
My working theory is that they were looking for some device that law enforcement had determined being utilized within the home based on cell records, internet provider records, or wi-fi device records/logs at some time prior to the events that took place October 15th and there was some expectation of finding the device in the home. The only things that come to mind are either a tablet or a phone - perhaps using wi-fi only in airplane mode.
I don't think they brought in the specialized K9 on a whim.
I had thought that bringing in the specialized K9 and then setting up surveillance cameras prior to very publicly announcing the scene was released (something we see rarely done) meant that law enforcement had some expectation that the person(s) responsible would return to the home to retrieve a particular device. Perhaps the two activities are not connected and were serving two separate purposes. I doubt it. But I find this to be a bit of a puzzle.