If the results of an investigation are only as good as the data it utilizes, then the recent investigation into the Las Vegas massacre is one for the record books – at the bottom of the list.

Predictably, Las Vegas Sheriff Joseph Lombardo reiterated the Las Vegas Metropolitan Police Department (LVMPD)'s preliminary findings in the final report: one and only one shooter, Stephen Paddock, was responsible for the carnage in the deadliest mass shooting in modern American history.  Other possibilities – including shooters at other locations on or near the Las Vegas Strip – he dismissed.  

Where is the muzzle flash?

While the report discusses weapons fired during the event, it does not mention recorded imagery of muzzle flash from the 32nd-floor window where Paddock was determined to have carried out his killing spree.  

Muzzle flash from weapons such as the AR-15 is one of the key indicators of shooter location, particularly in the thermal infrared, a region of the electromagnetic spectrum extending beyond the range that the human eye can see.  According to the report, Paddock used a total of 13 weapons during the shooting (not including the pistol with which he killed himself).  Even if some weapons were flash-suppressed, the incessant, continuous, violent barrage from one location should have produced some flashes whose signatures were captured on video – even on the cell phone camera videos taken by many individuals on the ground.  

Moreover, FBI forensic experts determined that some of the weapons had been loaded with tracer ammunition, making a signature more likely to be seen on imagery.  No discussion of flash or tracer signatures appears in the document, and no explanation for the omission is provided.

The good news is that the LVMPD infrared camera deployed on the night of 1 October appeared to be working properly, clearly showing the broken windows on the 32nd floor.  When the imagery was recorded is left to the imagination, as no time stamps appear on the video.  (Incidentally, the thermal imagery does not show the numerous reflections off the building from light sources below: artificial lighting is designed for the human visual spectrum, and this camera operates outside it.)

Where are the witnesses?

More interesting than the final report is this account of officers deployed in response to the crisis.  Personnel in one helicopter, Metro Air 5, "were able to determine that there appeared to be shots coming from an elevated position on the east side of Mandalay Bay."  Determine, how?  Did they see muzzle flash?  Hear gunshots?

While the crew did not observe broken windows at the time (what time?), due, they believed, to reflections off the building's side, they did note several possible firing locations: "the upper roof, the Foundation Room balcony [and] the lower casino roof[.] ... They then worked to clear the upper roof first, along with the Foundation Room balcony."

It is reasonable to assume that "to clear," in this context, means to direct people away from specific locations.  But why were people present on the hotel's upper roof during a shooting event, rather than seeking cover inside?  And who, exactly, has access to that area?

The Mandalay Bay tower is composed of 43 floors.  Paddock's suite on Floor 32 was in the lower segment, floors 1-34.  Floors 35-39 are managed by The Four Seasons Company, whose major shareholders are Saudi Prince Alwaleed bin Talal and Bill Gates.  Floors 40-42 contain penthouse suites, and Floor 43 (oddly numbered 63) is the aforementioned Foundation Room with a restaurant and lounge.  Guests on this level had a bird's-eye view of the tragedy unfolding below, yet their witness statements do not appear among those documented by LVMPD, which focused on hotel employees, police officers, and Paddock family members. 

Why not?

Where are the cameras?

Metro Air 5 later left this scene to respond to reports of a shooter in New York, New York, which it determined to be unfounded.  It next returned to the Tropicana to investigate another call but saw no sign of a disturbance.   The aircrew may not have known that the reported shootings occurred inside the properties, in lounges and casinos.

More than 500 911 calls appear in the records of that night.  The table below, which includes several links to audio files, offers a template that a thorough investigation might have followed before dismissing calls as unfounded.  While most events will not have officer body cam available, the inclusion of video from indoor closed-circuit television cameras (CCTVs) and traffic cameras on the streets would have allowed more detailed consideration of calls than the official approach provided.  It would also have facilitated comparison with individual videos such as this one, showing more than a dozen ambulances arriving and departing Hooter's Hotel following the massacre.

Suggested data to evaluate 911 calls

Muzzle flash imagery, statements from key witnesses, camera video…all of these sources would have provided a more robust dataset had they been included in the LVMPD investigation.  While that investigation has concluded, the dataset used to achieve the conclusion is far from complete.  

Barbara G. Grant is an electro-optical engineer and imagery analyst with three technical books in print.  She has investigated primary phenomena such as muzzle flash while studying the manner in which government investigations address controversial scientific issues and is looking for a publisher for a book explaining some of these technologies to the general public.

Image: Alicia Yo via Wikimedia Commons.