Drop the knife. Drop the knife. The parents' belief is irrelevent. They did not see it. We will never know.
Wild guesses serve no purpose other than to inflame people's emotions.
The officers did not ask the Seviers if anyone else was in the house. Not a routine 911 call. They may have been telling the truth regarding the Department's policies. There are still far too many wild guesses. It is correct that they could have done more and probably could have diffused the situation using different methods.