Hi Roger,
All 8 shots are for all intents and purposes identical in the cruiser audio. The echo starts about .1 seconds after the shot and peaks about .15 seconds after the shot. The echoes are weird, though, as they have a lot of higher frequency content that isn’t in the initial report. Here I show the frequency spectrum of the initial report and the echo for one shot.
The echo has a higher-pitched peak frequency than the original shot. The long fat tail on the echo spectrum means that if this is real, the cruiser glass isn’t muffling the shots too much. But the report itself has almost no energy above 2000 Hz while the echo does.
The only physical world explanation that even starts to address this is that the echo is of the bullet sonic signature that bounced off something in front of the shot–I don’t know what that would be, DJ Stewart (joking)? Even he was too far away for that.
But what really happened is the report inexplicably has no high-frequency content. It doesn’t match the echo or the noise spectrum of the rest of the audio.
So yes, there is an echo. Does it actually go with the report it follows or not? Seems like another potential contradiction with this source.