Explained: Why Airports and SGR Stations Have Multiple Security Checkpoints

Airports and major rail terminals, such as Jomo Kenyatta International Airport (JKIA) and Standard Gauge Railway (SGR) stations in Kenya, use multiple security checkpoints based on the 'defense in depth' principle. Each stage serves a distinct purpose: the first layer at the entrance detects obvious prohibited items, the second verifies tickets and identity, the third uses advanced scanners for weapons and explosives, and the final layer controls access at the boarding gate. This approach distributes security responsibilities among different agencies and reduces the risk of a single point of failure.