When an arrest is made without a warrant by an officer, he shall inform the person arrested of his authority and cause of the arrest; and when the arrest is made by a private person, he shall, before making the arrest, inform the person to be arrested of the intention to arrest him and the cause of arrest; except that when a person is engaged in the commission of a criminal offense, it shall not be necessary to inform him of the cause of his arrest.
(R.C. § 2935.07) (‘74 Code, § 32.11)