While it is a pitiful, shameful thing we have to have this knowledge and there certainly is no “one size fits all” lockdown protocol that will work in every school situation, acknowledging and planning for the worst could save a life. Several protocols were assessed and here are some of the findings to greater improve chance of survival:

-Don’t focus all of your efforts on active shooter situations. If lockdown training and drills are focused on active shooter situations, a higher fail rate occurs when other types of incidents occur or are simulated. The human brain is the most effective survival mechanism known to man — but only when properly prepared and research indicates that experiencing or simulating a wide range of crisis situations can prepare us to make life and death decisions more effectively.

-Schools that only have one type of lockdown procedure are more likely to have plan failure during a crisis. While it is normally good to keep things simple in school crisis planning, we have found that schools that only have one protocol based on active shooter situations and other crisis events have a high fail rate because school administrators are averse to overreacting in a situation they feel is too “minor” to warrant a lockdown. This can allow a situation to escalate into a deadly event because an early opportunity to lock down the building is missed. Having a lower level, “preventive” or “soft” lockdown option is important because most situations where lockdowns are needed do not involve weapons.

-Codes can kill. Plan failure has occurred in actual events and in evaluations because school staff members often confuse different codes when they are used in a crisis. For example, during a recent security assessment of a school district, administrators at 22% of schools accidentally orderedlockdowns instead of sheltering procedures in response to a tornado scenario and this could easily result in mass loss of life. In another district, a staff member at one school referred to a “code purple” protocol that was not listed in any plan and no other staff members referred to this protocol. The staff member was able to describe in detail what a “code purple” would entail, but there was no way to be sure that other staff members would know what to do when hearing this instruction.
-All staff should be issued keys, participate in staff development and some form of lockdown drill. If one door is not locked soon enough because a single employee is unable to lockdown, mass casualties can occur. It is important to allow staff the tools they need to keep the building secure throughout the school day and staff should be given ample practice in physically performing lockdown procedures before a crisis. People in a crisis often fail to perform seemingly simple tasks like evacuating a building or going around obstacles when it would be clear to any rational person that action should be taken. For example, in airplane accident where a passenger repeatedly pulled on her armrest instead of the emergency door release latch until another passenger reached over to help open the door (at which point the emergency door fell on the first passenger, injuring her and temporarily blocking the exit).-Doors should be locked during instructional times and when the door is not actively in use. Some schools require teachers to teach with their doors locked as a preventive measure. The way the school operates can impact the practicality of this approach, but in general it is only a small adjustment to make in the school culture.  Some educators feel that keeping doors open creates a positive and inviting environment, but from my experience a locked door does not have a negative effect on the class environment.  It has been observed that the more effective instructors kept the classroom door locked as a standard operating procedure. Aside from the safety benefits of doing this, it also creates an emphasis on timeliness, professionalism and discipline among students.

-If they are not trained with staff-initiated drills, individual staff members and teachers are less likely to respond effectively during a crisis. The threat that indicates the need for a lockdown often takes place in parts of the school away from the main office. This means that it is important to hold drills where different staff members are required to make the decision to initiate a lockdown without consulting with anyone. While the timing of the drill should be determined by the lead administrator or district office, individual staff should be required to make the lockdown decision after being prompted with a scenario. While many people assume that staff will perform how we want them to in an actual event, the incredible stress of a crisis has extreme effects on the human body. There is another case regarding the BeverlyHills Supper Club fire in which some employees looked for a supervisor to report the fire while a busboy started taking immediate action to evacuate the building, saving hundreds of lives that would have otherwise been lost due to a delayed response.

-Basing the lockdown decision on the location of the threat instead of the nature of the threat can be dangerous. Often referred to as lockout/lockdown protocols, taking this approach has a very high fail rate (81% in two of the districts we evaluated) because it is very difficult for employees to quickly decide which approach is best when they are presented with varying scenarios.  For example, in the scenario where there was a clearly suspicious individual who was not armed — an angry woman brandishing a knife in the front office or an intoxicated man brandishing a large crow bar in a hallway — most school employees did not order a lockdown at all when this type of protocol was in place. Past crises have shown us that people tend to act based on physical memory or the direction of others rather than internal rational decision-making.

-Reverse evacuation protocols and drills are critical. Lockdowns, sheltering procedures for severe weather and other critical life-saving protocols cannot be implemented as rapidly if there is no mechanism to promptly return students who are outside to the building in an organized fashion. While most school staff are already familiar with the basic concept of a reverse evacuation, very few understand it as a formal procedure and often delay action while considering what to do when they need to return to the building quickly.

-Room clear protocols can also be important. Schools must have a mechanism to quickly clear students from a room where there is a threat. One district uses the room clear procedure to send students to another part of the school quickly during a small crisis that does not require a school-wide evacuation but does necessitate quickly moving students away from a dangerous situation.  For example, when a student or a staff member has a medical emergency in a classroom, cafeteria or media center, the room clear protocol allows a staff member to quickly and safely send students to a pre-determined area nearby where they will be supervised by another staff member.

From http://www.campussafetymagazine.com/article/9-tips-for-more-effective-school-lockdowns#