Strict requirements and detection needs call for security checkpoints to perform efficiently even under very challenging conditions. The PMD2 Plus detects firearms and knives, even when they are hidden within body cavities, and accurately indicate the position of the threat, its intensity and its prevalent composition. The PMD2 Plus has a very low nuisance alarm rate even at the strictest Security Standards requested today, and therefore allows high transit flow rates and the minimum need for intervention by inspection personnel.