In planning for terrorist incidents, the primary objective is to move people away from danger. In this post, we cover the Second of three principal approaches: Lockdown.
Article 2 in a Series on Public Protection Procedures
This is the second article in our series, written by former counter-terrorism police and legal experts. It offers practical guidance for venues on the public protection procedures required to comply with Martyn’s law—and, above all, to keep people safe on your premises.
Introduction
Following the ratification of the Terrorism (Protection of Premises) Act 2025 in April 2025, venues that meet the definition of ‘qualifying premises’ must have appropriate public protection procedures in place by the end of the implementation period (the earliest possible date is April 2027). Where procedures already exist, venue operators should review and update them now to ensure they meet the new requirements.
This blog series is designed to support that process by offering practical guidance on the procedures venues may need to adopt.
In planning for terrorist incidents, the primary objective is to move people away from danger. There are three principal approaches, which we will cover in this series:
- Evacuation
- Lockdown
- Invacuation
These measures are not mutually exclusive; in some situations, a combination may be the safest option.
The previous blog examined evacuation: its variants and how to develop venue-specific policies and procedures. This instalment focuses on lockdown.
What is lockdown?
Lockdown is a protective tactic used when a life-threatening security threat exists outside a containable zone. It involves securing doors or other barriers to restrict access to all or part of a premises.
The objectives are to:
- Delay or deter attackers and reduce immediate threats.
- Prevent people from inadvertently moving into danger.
- Maintain control while directing people to safer locations.
A lockdown may follow an invacuation to a designated safe area. Depending on the situation, a partial lockdown and/or a directional evacuation may also be appropriate. Decisions should be based on a dynamic assessment of the premises and the evolving threat.
Timely action is critical. Do not delay a lockdown while awaiting police instruction if immediate measures are necessary to protect life.
Effective lockdowns can frustrate and slow attackers and significantly reduce casualties when an attack cannot be prevented. Evidence indicates that most fatalities in marauding attacks occur in the first few minutes; swift lockdown—especially when an attack begins outside a venue—can meaningfully reduce harm and may even deter entry. However, poorly implemented lockdowns can increase risk, so context and execution matter.
Types of lockdown
There are four main types of lockdown. Your choice should reflect the venue’s size, layout, occupancy, and the nature and location of the threat.
- One-way lockdown: Prevents entry while allowing people to exit.
- Two-way lockdown: Restricts both entry and exit.
- Partial lockdown: Secures selected doors (e.g., main entrance) while keeping some escape routes open.
- Zonal lockdown: Secures pre-designated areas within the premises.
While every venue differs, simplicity and clarity of purpose usually deliver the most effective response.
Developing your lockdown policy and procedures
Assess the premises
Define what lockdown means for your venue—this will vary by size, purpose and layout. For example, the NPSA describes a high-street theatre adopting a two-way lockdown of all external entry/exit points, a secondary lockdown of lobby doors, and a concurrent invacuation into the auditorium.
Large or complex premises may require multiple lockdown options. Identify all access/egress points and how each can be secured quickly and physically. Plan not only how to initiate lockdown rapidly but also how to lift it swiftly when necessary (e.g., in a fire).
Plan communications: how the decision to lock down will be conveyed, by whom, and what exact instructions people will receive (plain, factual, action-oriented language).
Review interactions with fire safety. Fire alarm activations may automatically unlock doors, potentially compromising lockdown. Understand these dependencies and mitigate them.
Lockdown policy
Your policy should set clear rules and decision-making parameters for responding to a developing threat.
Purpose and scope: Explain why the policy exists, where it applies, and what lockdown means at your premises, including the triggers that would prompt it.
Authority to act: Specify who can initiate a lockdown, prioritising those best placed to recognise danger and act without delay. Avoid relying on a single point of contact, as this can create delays. Instead, assign this authority to specific job roles (rather than named individuals) and ensure deputies are in place, so a lockdown can be initiated quickly if the primary lead is unavailable.
Identify critical actions: Clearly set out the key actions staff must take to implement an effective lockdown. Avoid assigning critical tasks to specific individuals only, as this can reduce the effectiveness of a lockdown if they are unavailable or not on site.
Communication: Describe how the decision will be communicated across the site, including channels, responsible roles, and the exact style of instructions staff and visitors should expect.
People outside / requests to enter or leave: Set out how you will handle those outside at the point of initiation and manage requests to enter or exit during lockdown. Balance the risk of bringing the threat inside against the vulnerability of those left outside.
Children and vulnerable people: Where unaccompanied children or vulnerable young people/adults are present, parents or guardians may head to the venue—sometimes before a police cordon is in place. Maintain a clear external communications plan alongside a robust internal warn-and-inform process.
Duration and welfare: Lockdowns may be brief or prolonged. If a systematic building search is required before the all-clear, they can last many hours. Plan for access to essential items (e.g., medicines) and secure storage of those items.
Assurance and training: Explain how the policy and procedures will be exercised, evaluated, and revised. Require regular, role-specific training so staff can perform their duties quickly and competently under pressure.
Test and exercise your procedure: Regularly exercise your lockdown procedure—either through tabletop scenarios or live drills involving all relevant staff. These exercises help identify critical actions and barriers to a successful lockdown and drive continuous improvement. They also strengthen staff knowledge, confidence, and readiness to act under pressure.
Write clear procedures
Translate the policy into clear, sequential actions.
Declaration: State who can declare a lockdown and on what criteria.
Alerting: Specify how the alert will be issued, by whom, and the exact wording so instructions are unambiguous.
Physical measures: Describe the immediate steps to secure the premises—what doors, shutters, and access points must be closed and precisely how to operate each mechanism.
Roles and positioning: Allocate responsibilities so every critical task has a clear owner—assigned to a job role rather than a named individual—and a defined order of execution. Specify where staff should position themselves during a lockdown to maintain control, support colleagues, and assist members of the public safely.
Contingencies: Include plans for conflicts with fire procedures, system or power failures, and rapidly changing threat dynamics, ensuring staff know how to adapt while preserving life safely.
Lifting the lockdown: Define who authorises the all-clear, how it is communicated, and the steps for a controlled return to normal operations.
A tailored approach to diverse premises
If you would like expert support to review your existing plans or to design a clear, practical lockdown procedure aligned to the Terrorism (Protection of Premises) Act 2025, get in touch with our team. We can help you assess risk and help produce concise, usable procedures that keep people safe.
We also design and run facilitated tabletop exercises so staff can rehearse roles, communications, and decision-making in realistic scenarios.
The National Protective Security Authority (NPSA) offers a free, publicly accessible guide covering policies and procedures for evacuation, invacuation, and lockdown. You can access it here.
Kevin Purcell
Kevin, United Outcomes’ Chief Operating Officer, boasts a distinguished career leveraging his background as a senior police officer to drive organisational excellence. With over a decade in leadership roles, Kevin excels in coordinating multi-agency operations, underscoring his adeptness in emergency preparedness. Specialising in change management, leadership, and development across various sectors, he has a record of executing projects efficiently, within budget, and to the highest standards.
