Laser jammer laws in California prohibit the device outright. Under Vehicle Code 28150, you cannot equip your vehicle with, use, buy, sell, manufacture, distribute, or even possess a device designed to interfere with law enforcement speed-measurement equipment. A first offense is an infraction. Get caught with four or more devices at once and it becomes a misdemeanor punishable by up to six months in county jail.
What Vehicle Code 28150 Prohibits
The statute operates in two parts. No vehicle driven on California roads may be equipped with any device capable of interfering with radar, laser, or other speed-measurement tools used by law enforcement. And no person may use, buy, possess, manufacture, sell, or distribute such a device. That second part catches people off guard. You don’t have to be driving with a jammer installed for it to be a problem. Buying one to keep at home, or selling one to someone else, falls under the same statute.
Officers don’t have to prove the jammer was powered on or actively disrupting a reading. If the hardware is installed on your vehicle or found in your possession, the elements of the offense are met. A powered-down jammer bolted to your bumper is still a violation. The presence of the equipment is the offense, not its performance at any given moment.
The statute isn’t limited to laser jammers either. CVC 28150 covers any device designed to interfere with “radar, laser, or any other electronic device” used for speed measurement, which means radar jammers are equally illegal under state law.
Fines for a First Offense
A standard violation of CVC 28150 is an infraction. The statute itself doesn’t set a unique fine schedule, so the base fine follows California’s general infraction guidelines. The number that actually appears on the citation is usually much higher than the base, because penalty assessments, court fees, and state surcharges stack on top. A fine that starts in the low hundreds can climb past $1,000 by the time all assessments are applied.
Because this is an equipment violation rather than a moving violation, a conviction generally doesn’t add points to your driving record. It does still appear on your record, and insurance companies can access that information when evaluating your policy.
When It Becomes a Misdemeanor
The misdemeanor upgrade triggers when you possess four or more jamming devices at one time, not when you accumulate four separate violations over the years. The statute reads that “when a person possesses four or more devices” in violation of the law, the offense becomes a misdemeanor. Someone caught with a trunk full of units, perhaps intending to resell them, faces a far more serious charge than someone with a single jammer on their bumper.
A misdemeanor conviction under California’s default sentencing rules carries up to six months in county jail, a fine of up to $1,000, or both. That $1,000 cap is before penalty assessments, which again multiply the final amount owed.
Radar Jammers Add Federal Exposure
Laser jammers operate using infrared light, which falls outside the Federal Communications Commission’s jurisdiction over radio frequencies. Radar jammers are different. Federal law under 47 U.S.C. § 333 prohibits anyone from willfully interfering with the radio communications of any station licensed or authorized under the Communications Act. Police radar guns operate on licensed radio frequencies, so jamming them violates federal law regardless of what any state statute says. The FCC can pursue civil penalties, and criminal prosecution is possible for willful violations. A radar jammer in California exposes you to both the state infraction under CVC 28150 and potential federal enforcement.
Radar Detectors Are Legal
Radar detectors are legal in California for private passenger vehicles. The distinction is that a detector passively receives radio signals already in the environment, while a jammer actively transmits signals to disrupt law enforcement equipment. Receiving is legal; transmitting to interfere is not.
If you mount a radar detector on your windshield, you still need to comply with Vehicle Code 26708, which restricts what can be placed on or near the windshield. The general rule prohibits any object that obstructs the driver’s clear view. For electronic devices such as GPS units, the law permits mounting in a seven-inch square in the lower corner of the windshield farthest from the driver, or a five-inch square in the lower corner nearest the driver. The statute doesn’t specifically name radar detectors, but keeping any detector within these size limits and positions is the practical way to avoid a separate obstruction citation.
Commercial Drivers Face Stricter Rules
If you hold a commercial driver’s license, the rules tighten. Federal regulation 49 CFR 392.71 prohibits both the use and possession of radar detectors in commercial motor vehicles. Devices that are perfectly legal in your personal car become illegal the moment you’re behind the wheel of a commercial vehicle. Motor carriers are also barred from requiring or permitting drivers to use them. This federal ban applies on top of CVC 28150, and the career consequences for a CDL holder can be far more damaging than the fine.
How Officers Find Them
Jammers typically come to light in one of two ways. The more common path is during a lidar speed check. When an officer’s lidar gun fails to return a reading on a vehicle, or returns erratic data, it signals that something is interfering with the beam, and that alone gives the officer reasonable suspicion to make a stop. The other path is visual identification during a stop for another reason, where the officer notices aftermarket sensors mounted on the front bumper or grille.
Because the statute treats the equipment’s presence as the offense, these cases are straightforward compared with most traffic citations. There’s no speed to dispute, no calibration records to challenge. Either the device is on the vehicle or it isn’t.