Safety & Security

Breaching Locked Doors

Twelve nationally and internationally experienced school safety experts performed a detailed post-incident evaluation of the 2013 active shooter and arson attack at Arapahoe High School, in Centennial, Colo., as part of an arbitration process. Littleton Public School District leaders, who requested the evaluation, were far more open and forthright in answering our questions than has been typical of other active shooter cases we have worked. At the beginning of the investigation, the district agreed that the final report would be released for wide public dissemination so other school officials could learn from any lessons gleaned in the process. The review team logged more than 1,300 staff hours while reviewing over 10,000 pages of documents, conducting interviews and site visits. The resulting 81-page report identifies valuable lessons learned and can be downloaded at

Confusion about keys and damage to the facility

Many schools rely on Knox boxes containing only one or two keys to allow emergency responders to rapidly open locked doors during rescue and clearing operations. Arapahoe High School had Knox boxes, and district operations personnel provided additional master keys to responding law enforcement officers. However, in the confusion of the event, problems with keys were encountered. The speed of the attack, the use of both a firearm and Molotov cocktails by the attacker, the size and complexity of the school design, the massive number of responding law enforcement officers and the tactics used by officers conducted the clearing operations created challenges. For example, three different teams where designated to sweep every square foot of the school in turn. Officers used a door marking system to ensure that every room was cleared three times. The decision was made for officers to use firefighters’ Halligan Tools to rip open a large number of doors because the keys did not get to some of the officers who needed them. Though officers followed training concepts and were naturally focused on finding any additional attackers, the breaching of doors caused significant physical and emotional damage that might have been avoided.

Trauma caused by rescue efforts

Compounding the physical damage were two challenges relating to the mental health needs of students and staff. The after-action review of the district’s recovery efforts revealed that many students and staff reported being more frightened by the clearing teams ripping doors open than they were from the sounds of gunfire during the attack. As teachers had been trained that responding officers would use keys to open doors, many assumed the sounds were being made by attackers. The recovery team requested that the district’s facilities personnel rapidly repair damage to the school from the attacker’s shotgun blasts, replace the damaged doors and doorframes, remove the door markings and repair damage from a fire in the library set by the attacker. In a truly amazing and commendable effort, the district’s facility’s team worked with a mitigation firm to make this request a reality.

Lives were saved but lessons learned

The report documents how the school’s emergency preparedness measures prevented this well-planned attack by a deeply troubled, heavily armed and intelligent student from becoming the mass casualty event he envisioned in his diary. While an innocent student was brutally murdered by the attacker, the amazingly fast and effective response of school staff combined with the presence of a school resource officer at the school denied him the opportunity to kill the large number of victims the former eagle scout desired when he planned his attack over a three-month time span.

Advance planning for proper key control under crisis conditions is also important. Littleton Public Schools had to rekey a number of locks because some of the seven keys they provided to law enforcement officers were not returned. In another example, one of our analysts found a grand master key to a school in a parking lot in the police staging area after a full-scale active shooter exercise in Oregon.

These situations demonstrate the need for thoughtful discussions between school and public safety officials. While proximity card systems can make this easier for some doors, officers will need access to all interior doors. The ability of responding police to rapidly obtain adequate numbers of master keys and printed floorplans can prevent significant property damage, minimize emotional trauma and could even save human life.

This article originally appeared in the issue of .

About the Author

Michael Dorn serves as the executive director for Safe Havens International, Inc., an IRS-approved, nonprofit safety center. He has authored and co-authored more than 20 books on campus safety. He can be reached through the Safe Havens website at