Judgment of the Court (Fourth Chamber) of 9 November 2023.#Staatsanwaltschaft Aachen v M.D.#Reference for a preliminary ruling – Judicial cooperation in criminal matters – Recognition of judgments imposing custodial sentences or measures involving deprivation of liberty for the purpose of their enforcement in another Member State – Framework Decision 2008/909/JHA – Article 3(4) and Article 8 – Refusal to enforce – Second paragraph of Article 47 of the Charter of Fundamental Rights of the European Union – Fundamental right to a fair trial before an independent and impartial tribunal previously established by law – Systemic or generalised deficiencies in the issuing Member State – Two-step examination – Revocation of the suspension attached to a custodial sentence imposed by a Member State – Enforcement of that sentence by another Member State.#Case C-819/21.