You picked the perfect word that ties much of this together: “bait.”
"There is no branch of detective science which is so important and so much neglected as the art of tracing footsteps." Sherlock Holmes in "A Study in Scarlet".
Follow the footsteps of KE and Howard. KE disappears to Ca. in both cases. Howard is "Alone" with both victims prior to discovery of death BY OTHERS!!
It is only these two people who were administering drugs...dangerous combinations of drugs...
We STILL don't know who wrote the prescriptions for Daniel but we DO know that Methadone was accessable to Howard.