Opinion of Advocate General Hogan delivered on 4 June 2020.#Criminal proceedings against ZW.#Request for a preliminary ruling from the Amtsgericht Heilbronn.#Reference for a preliminary ruling – Citizenship of the Union – Article 21 TFEU – Right to move and reside freely in the territory of the Member States – Criminal offence specifically concerning international child abduction – Restriction – Justification – Child protection – Proportionality.#Case C-454/19.