[muawiyah]

My hypothesis is modern air conditioning systems demand modern thermal insulation. This, in turn, provides really tremendous sound dampening. An indoor witness probably didn't hear much at all.

[Smokin' Joe]

I'm not saying that there are not circumstances which could lead to a witness only hearing the shot, and then as a 'pop' instead of a bang, or being oblivious to any commotion outside. Apparently one door which was not knocked on or doorbell rung belonged to the witness.

At the same time, I have trouble envisioning not looking out a window, checking the door before getting ready for bed, etc. All opportunities to become aware that something is going on on the witness' street.

But then, I live in a 90 year old house, and used to tend bar in a biker bar where the clientelle was pretty laid back until some wannabe came in and started something, so I have an eye/ear for trouble brewing. Anything out of the ordinary becomes the object of investigation.