The acoustic study that Martenson cites is from the University of Colorado fwiw.
They should be able to tell the difference of the sounds of different weapons.
...IF they are familiar with analyzing the sounds of gunshots.
All sorts of things can cause “differences”, such as the angle of the microphone (and case) to the gun, mic proximity to a human body, proximity of the gun to the roof, edge of roof, and so on.
With only the sound to go by, I’d say different guns and / or different shooter in a different spot. But, casings (fired cartridges) on the roof trumps that (so to speak.)