California Penal Code Section 12001.1

(a) Any person in this state who commercially manufactures or causes to be commercially manufactured, or who knowingly imports into the state for commercial sale, or who knowingly exports out of this state for commercial, dealer, wholesaler, or distributor sale, or who keeps for commercial sale, or offers or exposes for commercial, dealer, wholesaler, or distributor sale, any undetectable knife is guilty of a misdemeanor. As used in this section, an undetectable knife means any knife or other instrument with or without a handguard that is capable of ready use as a stabbing weapon that may inflict great bodily injury or death that is commercially manufactured to be used as a weapon and is not detectable by a metal detector or magnetometer, either handheld or otherwise, that is set at standard calibration. (b) Notwithstanding any other provision of law, commencing January 1, 2000, all knives or other instrument with or without a handguard that is capable of ready use as a stabbing weapon that may inflict great bodily injury or death that are commercially manufactured in this state that utilize materials that are not detectable by a metal detector or magnetometer, shall be manufactured to include materials that will ensure they are detectable by a metal detector or magnetometer, either handheld or otherwise, that is set at standard calibration. (c) This section shall not apply to the manufacture or importation of undetectable knives for sale to a law enforcement or military entity with a valid agency, department, or unit purchase order, nor shall this section apply to the subsequent sale of these knives to a law enforcement or military entity. (d) This section shall not apply to the manufacture or importation of undetectable knives for sale to federal, state, and local historical societies, museums, and institutional collections which are open to the public, provided that the undetectable knives are properly housed and secured from unauthorized handling, nor shall this section apply to the subsequent sale of the knives to these societies, museums, and collections.