2023 Wisconsin Statutes & Annotations › Chapter 941 - Crimes against public health and safety. › 941.31 - Possession of explosives.

941.31
Possession of explosives.
(1)
Whoever makes, buys, transports, possesses, or transfers any explosive compound or offers to do the same, either with intent to use such explosive to commit a crime or knowing that another intends to use it to commit a crime, is guilty of a Class F felony.
(2)
(a)
In this subsection, “improvised explosive device" means a destructive explosive device capable of causing bodily harm, great bodily harm, death or property damage; with some type of explosive material and a means of detonating the explosive material, directly, remotely, or with a timer either present or readily capable of being inserted or attached; which may include a pipe or similar casing, with the ends of the pipe or casing capped, plugged or crimped, and a fuse or similar object sticking out of the pipe or casing; and made by a person not engaged in the legitimate manufacture or legitimate use of explosives, or otherwise authorized by law to do so. “Improvised explosive device" does not include ammunition for any rifle, pistol or shotgun.
(b)
Whoever makes, buys, sells, transports, possesses, uses or transfers any improvised explosive device, or possesses materials or components with intent to assemble any improvised explosive device, is guilty of a Class H felony.
(c)
This subsection does not apply to the transportation, possession, use, or transfer of any improvised explosive device by any armed forces or national guard personnel or to any peace officer in the line of duty or as part of a duty-related function or exercise. The restriction on transportation in this subsection does not apply to common carriers. Notwithstanding s. 939.22 (22), this paragraph does not apply to a commission warden.
History:  1977 c. 173; 1987 a. 234; 1999 a. 32; 2001 a. 109; 2007 a. 27.
Sub. (1) is not unconstitutionally vague. An explosive is any chemical compound, mixture, or device, the primary purpose of which is to function by explosion. An explosion is a substantially instantaneous release of both gas and heat. State v. Brulport, 202 Wis. 2d 505, 551 N.W.2d 824 (Ct. App. 1996), 95-1687.
First-degree recklessly endangering safety is not a lesser included offense of s. 940.19 (5), aggravated battery. State v. Dibble, 2002 WI App 219, 257 Wis. 2d 274, 650 N.W.2d 908, 02-0538.
The court applied a dictionary definition of explosive material as “a substance that on ignition by heat, impact, friction, or detonation undergoes very rapid decomposition (as combustion) with the production of heat and the formation of more stable products (as gases) which exert tremendous pressure as they expand at the high temperature produced" in finding methyl ethyl ketone, commonly known as acetone, is an explosive material under sub. (2) (a). State v. Strong, 2011 WI App 43, 332 Wis. 2d 554, 796 N.W.2d 438, 10-1798.
A device qualifies as an improvised explosive under sub. (2) (a) even if it lacks a functioning detonator as long as a means of detonation can be readily inserted or attached. The defendant's devices met this requirement because the detonators could have been made operable with the insertion of two readily available parts. State v. Strong, 2011 WI App 43, 332 Wis. 2d 554, 796 N.W.2d 438, 10-1798.