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Forensic Acoustic Ananlysis of 2nd Shooter in Vegas
Posted on 10/13/17 at 7:55 am
Posted on 10/13/17 at 7:55 am
Posted on 10/13/17 at 7:59 am to Mulat
Cliffs? I cant watch a video at work
Posted on 10/13/17 at 9:05 am to Mulat
A competent acoustic analysis would likely prove that there were two shooting points, each with a different acoustic fingerprint.
A precise photograph of the shooter's vantage point would likely show two different windows where the shooter was shooting from, each with a different acoustic field and environment.
A person with even the most minimal intellect would conclude that this investigation did not take any detailed analysis. Just look at the scene of the crime, idiot.
A precise photograph of the shooter's vantage point would likely show two different windows where the shooter was shooting from, each with a different acoustic field and environment.
A person with even the most minimal intellect would conclude that this investigation did not take any detailed analysis. Just look at the scene of the crime, idiot.
Posted on 10/13/17 at 9:14 am to Mulat
So where was this mysterious shooter positioned exactly?
Posted on 10/13/17 at 9:25 am to Mulat
Nice TASC shirt
Posted on 10/13/17 at 9:29 am to Mulat
Are any of the shots overlapping?
Posted on 10/13/17 at 9:43 am to Mulat
This is a forensic acoustic analysis done by a guy who is involved in fricking food testing. The guy has absolutely no background that I can find in audio signal analysis or forensics.
He is relying on a number of assumptions we do not know to be true (the caliber of the weapon being a good one). He is using audio from cellphones, recorded in an open windy environment, then uploaded to youtube, then downloaded backdown. All of that significantly degrades the already poor audio recorded by mediocre microphones.
Also building an acoustic profile of an area as complex as the Las Vegas strip is a crazy difficult task. There are so many buildings and other echoes to take into account.
Tl;Dr video is suspect at best.
He is relying on a number of assumptions we do not know to be true (the caliber of the weapon being a good one). He is using audio from cellphones, recorded in an open windy environment, then uploaded to youtube, then downloaded backdown. All of that significantly degrades the already poor audio recorded by mediocre microphones.
Also building an acoustic profile of an area as complex as the Las Vegas strip is a crazy difficult task. There are so many buildings and other echoes to take into account.
Tl;Dr video is suspect at best.
Posted on 10/13/17 at 9:46 am to Mulat
I saw this a couple of nights ago and there are a couple of glaring issues:
1-it assumes only a single caliber. As someone else pointed out, different calibers would cause differing delays.
2- Even if you assume only one caliber, the differences could potentially be explained by a few things:
a- different bullet weights (55 gr, 62 gr, 75 gr, etc)
b- different powder loads (.223 vs 5.56)...more powder, higher muzzle velocity for a given bullet weight
c- different barrel lengths, the longer the barrel the higher the muzzle velocity, and vice versa
I haven't done any of the math to see if the differing report signatures he shows fall into a variance that could be caused by any of the variables above, but it's at least a possibility.
Also the fact that it's cell phone video is irrelvant, the quality of the audio is not important as long as the wave form signatures of the reports can be picked out, and from what he's shown it seems as though they can.
ETA: Echos are another possible reason for the variance. To rule that out you'd have to be sure to isolate the "bursts" . Obviously if there are two strings of reports happening at once, the fist question should be whether one of those is the result of the sound reflecting off of nearby buildings. He didn't go into this so we don't know how, or if, he went about isolating the strings of gunfire to ensure he was comparing the correct muzzle report sound to the corresponding bullet impact.
1-it assumes only a single caliber. As someone else pointed out, different calibers would cause differing delays.
2- Even if you assume only one caliber, the differences could potentially be explained by a few things:
a- different bullet weights (55 gr, 62 gr, 75 gr, etc)
b- different powder loads (.223 vs 5.56)...more powder, higher muzzle velocity for a given bullet weight
c- different barrel lengths, the longer the barrel the higher the muzzle velocity, and vice versa
I haven't done any of the math to see if the differing report signatures he shows fall into a variance that could be caused by any of the variables above, but it's at least a possibility.
Also the fact that it's cell phone video is irrelvant, the quality of the audio is not important as long as the wave form signatures of the reports can be picked out, and from what he's shown it seems as though they can.
ETA: Echos are another possible reason for the variance. To rule that out you'd have to be sure to isolate the "bursts" . Obviously if there are two strings of reports happening at once, the fist question should be whether one of those is the result of the sound reflecting off of nearby buildings. He didn't go into this so we don't know how, or if, he went about isolating the strings of gunfire to ensure he was comparing the correct muzzle report sound to the corresponding bullet impact.
This post was edited on 10/13/17 at 9:52 am
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