Possession of Materials to Make a Destructive Device or Explosive

California Penal Code § 18720

Overview

Under California Penal Code § 18720, it is a felony to knowingly possess substances or materials with the intent to make an explosive or destructive device. This law targets individuals who are preparing or attempting to manufacture bombs, grenades, or other destructive devices, even if the device is never completed or detonated.

Because this offense involves explosives, law enforcement, prosecutors, and courts treat these cases with extreme seriousness. Convictions can lead to years in state prison, permanent felony records, and significant collateral consequences such as the loss of firearm rights, employment restrictions, and immigration issues for non-citizens.

To convict someone under Penal Code § 18720, the prosecution must prove four essential elements beyond a reasonable doubt:

  1. Possession: The defendant possessed a substance or material that could be used to make an explosive or destructive device.
  2. Knowledge: The defendant knew they possessed the material or substance.
  3. Intent: The defendant specifically intended to use the material or substance to create an explosive or destructive device.
  4. No Permit: The defendant did not have a valid permit or legal authorization to make such a device.

Possession can be actual (on one’s person) or constructive (in a place the defendant controls, such as a vehicle, garage, or storage unit). The intent requirement distinguishes lawful ownership of chemicals, fuels, or reloading materials from criminal possession.

When Are Charges Filed?

A person may be charged under this statute when police or federal agents discover items such as gunpowder, dynamite, nitroglycerin, detonation cords, or precursor chemicals in suspicious circumstances. Evidence of intent can come from:

  • The presence of timers, detonators, or wiring.
  • Notes, diagrams, or online searches related to bomb-making.
  • Containers, pipes, or shells suitable for holding explosives.
  • Communications suggesting plans to use or test a device.

However, possession alone does not prove criminal intent. Many legitimate industries — mining, film production, pyrotechnics, and antique-firearm hobbyists — use controlled materials lawfully. Prosecutors must show that the defendant’s possession was tied to an intent to build a destructive device without authorization.

Examples

  • A hobbyist purchases black powder for antique muzzleloaders. If law enforcement finds fuses and containers, they may suspect bomb-making. Without proof of intent, this would not meet § 18720’s standard.
  • A person keeps gasoline and fireworks materials but also has written plans describing an “explosive device.” Combined evidence could justify charges.
  • A licensed pyrotechnician in possession of explosive components for film production would not be guilty because they hold a valid permit.

Penalties and Sentencing

Possession of materials to make a destructive device is a straight felony, meaning it cannot be filed or reduced to a misdemeanor. Penalties include:

  • Two, three, or four years in state prison.
  • Formal probation in limited circumstances.
  • Up to $10,000 in fines.
  • Permanent loss of firearm rights.
  • Collateral consequences, including immigration impact, job restrictions, and security-clearance issues.

Because this crime involves explosives, several enhancements and related statutes may increase exposure:

  • Location Enhancements: If materials were found near schools, airports, or public buildings, prosecutors may pursue additional time for endangering public safety.
  • Intent to Injure or Terrorize: If evidence suggests an intent to cause harm, terror, or public panic, additional felony enhancements can apply under Penal Code § 11418 and related anti-terror statutes.
  • Great Bodily Injury (GBI): If someone is injured or killed as a result of the possession or testing of explosives, a 3-to-6-year consecutive enhancement may be added under Penal Code § 12022.7.
  • Strike Offense: A conviction may qualify as a serious felony under California’s Three Strikes Law, doubling future sentences and imposing mandatory minimums.
  • Federal Exposure: In serious cases, defendants may face concurrent federal charges under 18 U.S.C. §§ 842–844, which carry harsher penalties and mandatory minimums for bomb-related conduct.

Given the overlap between California and federal jurisdiction, early representation by experienced counsel is critical.

Common Defenses

Every element of this crime requires proof of knowledge and intent. Effective defenses often target those two areas.

1. Lack of Intent

A defendant may have possessed the materials for a legitimate reason, such as ammunition reloading, scientific work, or pyrotechnic hobby use. Without proof of an intent to build a bomb or destructive device, the charge fails.

2. Lack of Possession or Control

If the materials were located somewhere the defendant did not control — for example, in a shared residence, vehicle, or workspace — the prosecution cannot prove possession.

3. Valid Permit

A valid federal or state explosives license or permit is a complete defense. The burden rests on the prosecution to prove that no valid permit existed.

4. Illegal Search and Seizure

Explosives cases often stem from searches of homes, garages, or digital devices. If police exceeded the scope of a warrant or lacked probable cause, evidence can be excluded under the Fourth Amendment, often leading to dismissal.

5. Insufficient Evidence

Prosecutors may rely on circumstantial inferences such as internet searches or possession of chemicals found in household cleaners. A skilled defense attorney can demonstrate that these facts are equally consistent with innocent behavior.

Building an Effective Defense Strategy

Defending a Penal Code § 18720 case requires both technical understanding of explosive materials and legal expertise in handling felony prosecutions. The defense strategy may involve:

  • Expert testimony to explain the legitimate uses of the materials.
  • Independent testing of seized substances to confirm whether they were actually explosive.
  • Cross-examination of investigators regarding training, evidence handling, and assumptions about intent.
  • Negotiation with prosecutors to reduce charges to lesser, non-explosive offenses such as possession of hazardous materials or reckless endangerment.

Because intent is the heart of this charge, experienced attorneys focus on reframing circumstantial evidence and introducing reasonable doubt about purpose and control.

Why You Should Hire Radford & Rome, LLP

Possession of explosive materials is not treated like an ordinary felony. These cases attract specialized law-enforcement units, aggressive prosecution, and sometimes federal oversight. The potential consequences — prison time, loss of civil rights, and lifelong stigma — are too serious to face without expert representation.

At Radford & Rome, LLP, our attorneys are former prosecutors who have handled complex felony and explosives-related cases throughout Southern California. We understand how investigators build these cases and how to challenge the government’s theories using science, procedure, and persuasion. We conduct detailed factual investigations, file strategic motions to suppress evidence, and negotiate with prosecutors to secure charge reductions or dismissals whenever possible.

If you have been accused of possessing materials to make a destructive device or explosive, contact Radford & Rome, LLP immediately for a confidential consultation. Our firm serves clients across Los Angeles, Orange, Riverside, and San Bernardino Counties. We will evaluate your case, explain your rights, and fight to protect your future.