Aftermath of the Las Vegas Mass Shooting: A Look at How Investigators Process Mass Casualty Crime Scenes

Grizzly and horrific scenes are just part of the job when you gather evidence and process crime scenes for a living – even on normal days. Dark deeds and depressing stories of the depths of man’s inhumanity to man become commonplace, even grist for the kind of black humor that keeps you sane through it all…

But sometimes, something so massive and so horrific comes upon you that even the most hardened investigators are left silent and overwhelmed.

A Horrific and Massive Scene Demanding Meticulous Professionalism

On the evening of October 1st, 2017, supervisors and analysts for the Crime Scene Investigations Section (CSIS) of the Las Vegas Metropolitan Police Department rolled up on such a scene, one of baffling complexity and impossible chaos that left the entire country reeling.

Strobes from patrol vehicles and ambulances cast red and blue light across the 15-acre lot of the Las Vegas Village, an open-air concert venue adjacent to the Mandalay Bay Resort and Casino. In the splashes of light, the movements of first responders appeared jerky and wooden. Piles of abandoned clothing, drink containers, bags, and other personal items littered the field in front of the empty stage.

Blood pooled and trickled around the debris. And across the asphalt, still shapes of crumpled bodies could be seen… dozens of them, alone and in clusters. The body count would eventually grow to 58 as some of the wounded passed away in nearby hospitals, and others expired in ambulances while being attended to en route.

This gruesome scene was what investigators faced in the aftermath of what would soon be recognized as the worst mass shooting in American history.

The country wanted answers. The fifty-two members of the LVPD CSIS, together with federal resources from the FBI (Federal Bureau of Investigation) and ATF (Bureau of Alcohol, Tobacco, and Firearms), were responsible for finding them.

A Crime Scene Spanning the Concert Venue, the Suite at Mandalay Bay, the Shooter’s Homes, and McCarran Airport

Bodies were still being removed from the scene sixteen hours later as the afternoon sun beat down from overhead. The plaintive chimes of cell phones that would never be answered rose from the debris as desperate friends and family attempted to contact the dead. And crime scene investigators faced the daunting task of evaluating a scene where hundreds of bullets had landed and hundreds of people had been shot, with no obvious motive and enormous uncertainty about the background of the attacker.

Investigators spent a week at the concert venue scene itself, combing through thousands of discarded personal effects, trash, and equipment for spent rounds and other evidence. The volume of items reviewed was unprecedented. With more than 10,000 pieces of evidence filling seven large box trucks collected from one section of the scene alone, this could possibly be the biggest collection of evidence from any American crime scene since 9/11.

To attempt to make processing more efficient, the concert venue was broken down into areas and subareas. As an area of the venue was processed, items that were deemed unnecessary for evidence were released in batches and turned over to the rightful owners.

And the crime scene wasn’t just limited to the concert venue. The large suite at the Mandalay Bay from which the shooter had opened fire had to be processed, as well as homes he had owned in Reno, Mesquite, and Melbourne, Florida. Rounds were found to have been fired at fuel storage facilities at nearby McCarran International Airport, requiring technicians to comb the area for bullets and spent casings for ballistics testing. Twenty-three firearms and a large quantity of ammunition were found in the hotel room, along with surveillance devices. More firearms, ammunition, and explosives were located at his homes.

Such vast crime scenes are inevitably highly contaminated. Twenty-two thousand concertgoers were present at the Las Vegas venue, joined by hundreds of first responders while the incident was underway. The first priority is always to save lives and eliminate active threats, so concerns about preserving the scene were far from the minds of anybody while the shooting was taking place.

IEDs Represent a New and Increasingly Present Threat for Investigators

These days, in a situation like this, active threats aren’t just limited to the shooter or shooters either. They also include improvised explosive devices (IEDs), such as those employed in the aftermath of the Boston Marathon Bombing and the San Bernardino mass shooting.

The possibility of such stay-behind threats are often present these days and are very real. Investigators can quickly become victims themselves if bomb squad screening isn’t done before crime scene technicians and investigators take control of the scene. Yet the traditional way of eliminating those devices involves blowing them up, further destroying or damaging potential evidence.

After the dust settles and the scene has been swept for IEDs, there is virtually no chance of getting a clean scene, yet valuable evidence still exists and must be identified, gathered… and anything that might be contaminating that evidence must be separated and documented.

Marshalling Technology to Investigate Mass Casualty Crime Scenes

Technological advances in crime scene investigation in some ways make mass casualty incidents more difficult to investigate rather than easier. The technical ability to analyze and detect even trace amounts of explosive material or DNA samples caused Boston to shut down ten blocks in the Back Bay neighborhood after the 2013 Boston Marathon Bombing in order to allow investigators to gather bomb debris and other evidence. The search took them through sewers and onto rooftops in a meticulous grid search pattern, with every square foot numbered and cataloged lest a single vital piece of evidence be missed.

The ubiquitous presence of cameras and recording devices is a boon to recreating the events of modern crimes. In the Boston marathon case, for example, analysis of commercial security camera footage was critical in providing an early break in the investigation. In the case of major, highly public events, it can take hundreds or thousands of man-hours and specialized analytical expertise to look through recordings to determine whether or not they contain useful evidence.

Electronic recordings, at least, pose only organizational and processing challenges. Physical evidence at large-scale incidents is another story. An entire warehouse was used for bomb debris evidence in Boston; in San Bernardino, almost 2,500 rounds of ammunition were collected from the suspect’s vehicle—which itself had absorbed another 440 rounds fired by police.

How Media Coverage Can Create More Problems Than it Solves

The modern media environment presents another challenge. The 24-hour news cycle presents constant demands for answers and new information, a pace that even the best forensics team is unlikely to match. In addition to the implied pressure of those demands, the need to produce new and sensational storylines pushes some reporters beyond the boundaries of law and propriety. In 2015, San Bernardino police were swamped by media demands after the social-services center shooting that killed 14, and over-enthusiastic TV reporters contaminated one of their scenes before it had been fully processed.

And media attention can lead to additional interference from the public as civilians take it upon themselves to join the hunt. The Las Vegas Review-Journal reported on October 11th that one of the homes of the suspected Las Vegas killer had been broken into the weekend after the shooting. No suspects have been identified and their motives or actions inside the home remain unknown… yet the incident may lead to further questions about evidence gathered there that could be significant to the investigation.

Lessons Learned From Past Incidents Make Mass Casualty CSI More Effective

Lessons from previous mass-casualty shooting incidents, such as those in Newton, Connecticut and Aurora, Colorado, have shown that planning is vital with such large and confusing scenes. It’s not enough to simply show up and work systematically. An initial walkthrough and elaborate video documentation of the scene creates a basis for building a plan for processing the site.

The flood of resources that become available from outside agencies can also be overwhelming to local CSI units unfamiliar with the capabilities and processes of those units. Yet incorporating the firearms and ballistics expertise of ATF technicians with the forensics capabilities of FBI Evidence Response Teams can lead to big, fast breaks. In Newtown, for example, expert ATF analysts were quickly able to establish the provenance of the shooter’s guns, helping local investigators piece together events leading up to the crime.

Local police investigators and technicians have to quickly adapt to becoming organizers and planners rather than simply focusing on the mechanics of the investigation.

The FBI, in particular, has been practicing techniques for handling large, sometimes separate, mass-casualty scenes. In the wake of the Paris Bataclan Theater attack, the bureau’s 56 Evidence Response Teams began practicing forensics processing at such scenes… something that was, unfortunately, put into practice only weeks later at the Orlando Pulse Nightclub massacre.

The need to preserve evidence is now even on the radar for fire and medical first responders. A 2014 article in the Journal of Emergency Medicine highlights steps that medical responders can take to reduce scene contamination at mass-casualty incidents.

One point from the article is that personal protective equipment, increasingly common among first responders, can help protect the crime scene as well as medics. But in Las Vegas, much of the initial aid was rendered by bystanders, unequipped with such gear and unable to be corralled for elimination printing.

It’s not just American incidents that have been informing new CSI procedures. Lessons can also be learned from overseas, where high-impact, mass-casualty events have been common for some time. In Israel, for example, new procedures for rapidly clearing scenes were developed to reduce exposure of CSI units to further attacks.

Although everyone both in and outside the CSI community fervently hopes never to have to use these procedures, you can bet investigators and crime scene technicians will be ready for the next event wherever and whenever it might occur.