How Inept Is The Frisco PD?

They held a news conference this afternoon on the death of the Frisco couple. The female in the pool had no trauma to her body. The father, found inside the home, had "trauma" to the head and a hand fracture. There was also a note -- which they won't release. And the Chief is already throwing up his hands and saying, "We may never know" what happened? Yet they pursued the child's death as a murder case even when the ME ruled  he died of undetermined causes but stated, “Natural disease is most likely” the cause of death.