By noon or shortly after, all of the pieces of the response puzzle were in place. In the very first minutes of the incident and over the next several hours, many obstacles and concerns came to light that needed to be addressed by those at the command post, including: 

  • Number of Shooters – At one time or another, the number of shooters believed to be involved in the incident ranged from two to eight. Differing descriptions of the gunmen, different reports of their locations inside the school, the sheer volume of calls received about sightings and knowledge related to the incident, different observations made by law enforcement officers around the school, the number of explosions occurring, and the number of victims all played a part in the challenge to identify how many shooters were involved and where they were in the school. Additionally, there were erroneous reports that a suspect had left the school.


  • Entry into Building -- Sheriff’s deputies began arriving at Columbine High School within minutes of the attack. The deputy assigned to the school engaged one of the suspects in a gun battle as soon as he stepped out of his patrol car. Acting on years of training, other deputies hastily established a perimeter to prevent the escape of the gunmen. Deputies and officers from other agencies assisted escaping students to safety and rendered aid to the injured. The Sheriff’s SWAT commander arrived at the scene within 15 minutes of the first shots that were fired. He identified other tactical officers at the scene and began to assemble an ad hoc team representing three agencies. Officers who did not know one another, much less having trained together, entered the school not knowing how many suspects they might face, their locations, whether hostages had been taken, and with their sensory and communication abilities severely impaired. Meanwhile other officers and SWAT teams arrived to assist amid reports of possible snipers and multiple shooters wearing body armor and armed with automatic weapons and explosives. The long-established SWAT practice of “time, talk, and tactics” was discarded out of necessity.


  • Containment – One of the most significant challenges in any law enforcement situation is the containment of a scene. In a situation such as the one faced at Columbine, it is critical to the safety of the public at large that the gunmen not escape. On April 20, law enforcement established a perimeter around the school within minutes of their arrival. Deputies moved into positions to rescue and provide protection for the many children who ran to them for safety, to protect other people who might try to rush into the school, and to prevent the gunmen from getting out. If portions of the perimeter were not in place around the school, the suspects could have slipped out one of the building’s 25 exits – potentially harming innocent students and staff seeking safety away from the school and also taking their wrath into the larger community.

    When the gunmen’s bodies were discovered in the school library with self-inflicted gunshot wounds, law enforcement also found numerous unexploded devices, knives, firearms and rounds of live ammunition, more than enough to kill all 56 people initially in the library. By the number of weapons and ammunition found with them, it was apparent that Harris and Klebold were prepared to kill or maim many more than the 13 who died at their hands that day. The number of law enforcement officers on scene within minutes of the reported shootings plus the entry of SWAT inside the school minutes before their suicides denied the gunmen additional time to plan further actions or take other lives or hostages.


  • Escaping Suspect (s) – There was a report that a suspect had escaped the school. Law enforcement officers on scene were concerned of who might be behind them and who might be a threat to those groups of students they were protecting. An additional concern was that if a suspect escaped Columbine High School, where was he or she going and what was the next target?


  • Medical Assistance for Victims – The continued flow of injured victims to medical assistance was being accomplished by transporting victims to one of four triage sites set up in the area. After receiving emergency medical aid, the injured were transported to one of six regional hospitals. Shortly after noon, medical personnel came in too close to the school to rescue several wounded students and were fired on by at least one suspect. Law enforcement personnel provided cover fire to protect the students’ evacuation. As the situation progressed, medical personnel moved closer to the school in order to get medical assistance to the wounded as quickly as possible.


  • Sniper (s) – There were reports of snipers on the roof of the school, which could have had an effect on the response and the ability to approach the scene. As it turned out, there was an innocent person on the roof of Columbine High School but, at the time, the proper assumption was that he or she was a suspect/sniper.


  • Bombs – There were continued reports of bombs exploding -- a diversionary device near Wadsworth Boulevard and Ken Caryl Avenue, outside the school, inside the school, and the discovery of two car bombs in the student parking lot set on timers. Bomb technicians investigating the initial diversionary bombs realized that similar bombs with timers and motion-activated devices could have been placed at the school and relayed that information to the command post. Ultimately, bomb technicians responded from several different agencies to safely handle explosive devices as the incident progressed.


  • Hostages – There were numerous reports of hostages throughout the school. This information came from people within the school and from law enforcement officers who interpreted their observations. Even as late at 2:26 p.m., a report of possible hostages inside the school was relayed. Throughout the incident, every room and every contact was managed as though it was a potential hostage situation. When there was no active gunfire, the likelihood that there was a hostage taker with hostages increased with each passing moment.


  • Fleeing Students – Somehow, fleeing students of Columbine High School needed to be gathered and interviewed about their observations of what was occurring in and around the school. Potentially, some of the fleeing students could be accomplices of the crime that was occurring.


  • Fire – Littleton Fire Department was responsible for the management of the emergency medical treatments and the preparations for a possible fire or explosion inside of the school. At least one fire was handled by the fire sprinkler system in the school but there remained the potential for more serious fires and explosions. Adding to the concerns were reports of natural gas odors in the building and the possibility of a natural gas leak.


  • Arriving Parents – As word spread of the shootings at Columbine High School, parents were responding to the area to obtain information on the welfare of their children. The challenge of how to assist the parents of close to 2,000 students and continue to manage the incident unfolding at the high school was staggering. Leawood Elementary School and Columbine Public Library were used as central points to reunite parents with their children and as points where the Jefferson County School District could disseminate information about the whereabouts of students.


  • Evacuations – As the incident seemed to grow in size and complexity, the need for evacuations of innocent parties became evident. For their own safety and for the protection of the public, homes and curious people too close to the area were evacuated.


  • Media – Public Information Officer Steve Davis arrived and coordinated the release of information through Sheriff Stone and Undersheriff Dunaway. Hourly briefings were held to accommodate the need for the information. Also, television helicopters were initially hovering around the school to get their story. While the news helicopters assisted law enforcement by surveying the rooftops and the grounds, there was also the concern that images aired live might be seen by suspects inside the school. Those suspects might be watching the television broadcasts while in the school and would be able to anticipate or react to the actions of law enforcement outside.


  • Investigation – Lt. John Kiekbusch of the Sheriff’s Office Investigation Unit coordinated the start-up of the investigation and utilized investigators from numerous agencies to collect and report information coming out of the school, interview witnesses, secure crime scenes related to the crimes (homes of the suspects, etc.), and prepare warrants based on initial interviews. The Jefferson County Critical Incident Team for officer-involved shootings was also activated.


  • Traffic – With most of Pierce Street, Bowles Avenue, Fair Avenue and the surrounding neighborhoods at a standstill, it was imperative to keep citizens out of the area while still allowing authorized personnel into the area. Additionally, a clear path had to be established for ambulances transporting victims to area hospitals.


  • Alarms – The piercing sound of alarms going off in the school was a hindrance to law enforcement personnel trying to search inside. The control panels to shut off the alarms were in an unsecured area of the school so the alarms could not be silenced until much later in the afternoon.


  • Other Potential Sites – The command post personnel worried that, if an organized group had put together the plan of the tragedy now unfolding at Columbine High School, other places might be targeted as well. If the enemy was an organized terrorist group, a similar incident or a “phase two” might take place at a nearby high school. Additionally, there was the possibility that the situation at Columbine was intended to divert law enforcement from other crimes to be executed elsewhere. If either of those scenarios became reality, law enforcement would have to respond and also deploy resources to those sites. Strategies to deal with another incident that might occur simultaneously were discussed by several commanders to ensure a response if the need did arise.


  • Suspect Homes – After it was determined that Harris and Klebold were potential suspects, investigators and bomb technicians were dispatched to respond to their homes and secure the scenes at the residence and adjacent neighborhood until search warrants could be obtained.


  • Crime Scene – Even before the incident was over, lab and evidence personnel were already planning the processing and handling of the crime scene. They had to consider not only the school itself, but the suspects’ homes, the site of the diversionary devices and the school grounds and surrounding areas had to be addressed.


  • Responding Agencies – Individuals as well as agencies came to the aid of the Jefferson County Sheriff’s Office on April 20. The organization of the responders into worthwhile, functional components ensured that all of the tasks at hand were accomplished.


  • Continuing Updates From Within the School – As the incident progressed, further reports of possible hostages and locations of the shooters continued, often conflicting with other reports also being received. The differing reports, combined with the time necessary to safely evacuate students and staff from locked and barricaded areas, slowed the search of the school.


  • SWAT Tactics – Due to Lt. Walcher’s seven years of previous experience on the Jefferson County Sheriff’s Office SWAT team, he knew what tactics and building search methods were being used. In the past, the Jefferson County Sheriff’s Office SWAT team has trained where there have been “active shooters” or “target rooms” that had to be immediately assaulted. However, shortly after noon on April 20, the reports of active shooters declined (while still receiving reports of hostages) leading everyone to assume that the shooters were taking hostages and/or setting up for law enforcement personnel. As Investigator Al Simmons later told Walcher, “around every corner or through every door, I thought the gunfight was on.”

    This search, in such a large building, was a slow process. Rescuing students and staff in barricaded rooms where they would not open the doors, checking ceilings for potential suspects, checking all evacuees for weapons (who might be one of the suspects), evacuating students in the safest way possible to ensure they could not be injured by potential remaining suspects, and working around explosive devices that were located throughout the school were some of the challenges that SWAT teams had to deal with. Additional challenges included the distracting noise of the alarms, choking smoke that obstructed their vision, and ankle deep water in some areas as a result of active fire sprinklers.