How does the above statement which is NOT a direct statement from the police themselves and states that police are probing the "possibility" of a murder-suicide indicate that the police are looking at this solely as a murder-suicide case? Obviously, they aren't based on actions like impounding Honey's car, doing a sewer sweep, etc. Also, it's the job of the investigators to obfuscate the truth to the public at this point.
Clearly we have a different understanding of "police sources". I interpret this to be a statement made by police officers involved in the discovery of the bodies and valid information.
I also know that the family doesn't like the conclusion of the police and have demanded that the deaths be investigated as murders. Since that time, the homicide team is doing what they do at a real murder scene. That doesn't mean that because police are doing what the family demanded, the couple were murdered.