a barbed device on a pole that is attached to the neck of offenders being brought to justice

Catchpole is a rare surname derived from a law enforcement implement found in medieval England. The 'catchpole' usually consisted of an eight foot wooden pole with some sort of noose or barbed fork on one end. Law enforcement officers (usually the Sheriff) would place the noose around the neck of the criminal and use it to lead them around and so forth.

Operational code name for the US assault on the Marshall Islands, 1944