Civil law and liability
Civil liability determines who pays for damage. Distinguish contractual liability (breach of the security contract with the client) from extra-contractual/tort liability (Article 1382 old Civil Code / Book 6 new Civil Code: fault, damage, causal link). A guard who negligently fails to check a delivery and a theft follows may expose the employer to contractual liability toward the client, and the employer may then seek recourse against the employee for gross or intentional fault.
Key concepts: vicarious liability of the employer for employees acting in the course of employment; personal liability of the guard for intentional or grossly negligent acts; damage (material, moral, bodily); causation; and insurance (professional liability insurance is required for licensed security undertakings). Know also custody of goods and the limits of a guard's responsibility for visitors' property, and the burden of proof (the claimant proves fault, damage, and link).
Traps: (1) assuming the guard is always personally liable - usually the employer is liable toward the victim, with internal recourse; (2) confusing criminal conviction with civil compensation (both can follow the same facts); (3) forgetting that a contractual clause cannot exclude liability for intentional fault; (4) mixing guardian liability for objects/animals with personal fault.
Worked example: A guard leaves a gate unlocked contrary to procedure; a thief enters. The client sues. The employer is contractually liable for the guard's fault in performance of the contract; the guard may face disciplinary and recourse action if the fault was gross. Rule of thumb: follow the procedure in writing - the log is your proof of due care.
Also know the new Belgian Civil Code (Book 5 and Book 6) replaced parts of the old code from 1 January 2023; concepts remain similar but terminology changed.