As per case facts, the appellant, the alleged driver of a car involved in a fatal hit-and-run, was arrested but claimed his arrest was illegal because the grounds for his ... arrest were not furnished to him in writing, as mandated by the Constitution and procedural law, leading him to appeal the Bombay High Court's decision upholding the arrest. The question arose whether in all cases, including offenses under the BNS 2023, it is mandatory to furnish the grounds of arrest to the accused in writing immediately, and whether non-compliance vitiates the arrest even in exceptional circumstances. Finally, the Supreme Court ruled that the constitutional mandate under Article 22(1) for informing grounds of arrest is mandatory for all offenses, with the mode of communication to be in writing in the language the arrestee understands; in exceptional cases where immediate written communication is impractical, it can be done orally but must be provided in writing at least two hours prior to the remand hearing, with non-compliance rendering the arrest and subsequent remand illegal.