No they are not legal in any state.
Radar jammers are illegal in all 50 states.
Radar jammers/detectors are legal in every state but Virginia and the District of Columbia.
Active radar jammers are illegal in Ohio, but passive jamming is permitted. No -- Radar jammers are illegal in all 50 states.
Radar detectors are legal in the USA except in Virginia, Washington DC and on all military bases. Radar Jammers are illegal in Nebraska, Minnesota, Utah, California, Oklahoma, Virginia, Colorado, Illinois and Washington DC.
Radar jammers are illegal to own and/or operate in all 50 states per the Federal Communications Commission.
They are legal in all states except Nebraska, Minnesota, Utah, California, Oklahoma, Virginia, Colorado, Illinois, and Washington D.C.
Radar Detectors in Oklahoma: Radar detectors are legal to use in Oklahoma.Laser Jammers in Oklahoma: Laser jammers are illegal to use in Oklahoma.Courtesy of: http://www.1stradardetectors.com/radar-detector-laws.php
According to Michigan.gov Radar Jammers have been ruled illegal in all fifty states by the Federal government. In Michigan the state sites says that it's legal to use radar detectors in private vehicles. I take that to mean it might not be legal to use one in a commercial vehicle like a 18 wheeler.
If you are looking to jam the police frequency, you are out of luck in the US. It is illegal to use a radar jammer in all 50 states.
You can get radar detectors from Bestbuy.com and from Amazon.com. You should make certain that these devices are legal in the state you reside. In many places like Virginia they are illegal.
Radar laser detectors and laser jammers are legal to own and operate in passenger vehicles in the state of New York. Currently the only state that it is illegal to operate a radar detector is Virginia and Washington D.C.
Minnesota Radar and Laser Jammer laws Radar laser detectors are legal to own and operate in passenger vehicles in the state of Minnesota. Currently the only state that it is illegal to operate a radar detector is Virginia and Washington D.C. Laser jammers are illegal to operate in the states of: Nebraska, Minnesota, Utah, California, Oklahoma, Virginia, Colorado and Washington DC. Radar jammers are illegal to own and/or operate in all 50 states per the Federal Communications Commission. Radar detectors are also illegal in commercial vehicles weighing over 10,000 pounds in all fifty states, per Title 49 Transportation Act. Radar detectors are also illegal to operate on any military base.