Case T-502/16: Judgment of the General Court of 20 November 2019 — Missir Mamachi di Lusignano and Others v Commission (Civil service — Officials — Murder of an official and his wife — Obligation to ensure the safety of staff in the service of the European Union — Liability of the institution for non-material damage suffered by the family members of a deceased official — Mother, brother and sister of the official — Action for damages — Admissibility — Standing to bring proceedings under Article 270 TFEU — Person covered by the Staff Regulations — Reasonable period of time)