Restricted Areas.
Washington prohibits the knowing possession or control of a weapon in select areas, including:

• the restricted access areas of a jail, or of a law enforcement facility, or any place used for the confinement of specified persons;
• those areas in any building which are used in connection with court proceedings, including courtrooms, jury rooms, judge's chambers, offices and areas used to conduct court business, waiting areas, and corridors adjacent to areas used in connection with court proceedings;
• the restricted access areas of a public mental health facility licensed or certified by the Department of Health for inpatient hospital care and state institutions for the care of the mentally ill, excluding those facilities solely for evaluation and treatment;
• the portion of an establishment classified by the state liquor and cannabis board as off-limits to persons under 21 years of age; and
• the restricted access areas of a commercial service airport designated in the airport security plan approved by the federal Transportation Security Administration, including passenger screening checkpoints at or beyond the point at which a passenger initiates the screening process.

The perimeter of any location covered by these restrictions must be posted at reasonable intervals to alert the public of the restriction.

Exceptions.
The foregoing restrictions on weapons in specified areas of jails and law enforcement facilities, courts, mental health facilities, liquor and cannabis establishments, and airports do not apply to: 

• law enforcement personnel, subject to specified exceptions;
• security personnel while engaged in official duties;
• correctional personnel or community corrections officers, as long as they are employed as such, and have completed government-sponsored law enforcement firearms training, subject to specified exceptions; or
• any person engaged in military activities sponsored by the federal or state governments, while engaged in official duties. 

The restriction on weapons in specific areas of jails and law enforcement facilities does not apply to a person licensed to carry a concealed firearm pursuant to Washington law who, upon entry, directly and promptly proceeds to the administrator or their designee and obtains written permission to possess the firearm while on the premises or checks the firearm. 

The restriction on weapons in specific areas of public mental health facilities does not apply to the administrator or employees of the facility, or to any person who, upon entry, directly and promptly proceeds to the administrator or their designee and obtains written permission to possess the firearm while on the premises. 

The restriction on weapons in specific areas of liquor and cannabis establishments does not apply to the proprietor of the premises or his or her employees while engaged in their employment. 

Penalty.
Any person who violates the foregoing restrictions on weapons in specified areas is guilty of a gross misdemeanor.

Definitions.
For the purpose of the restriction on weapons in specified areas of courts, "weapon" means any firearm, explosive, or any weapon of the kind usually known as a slungshot, sand club, or metal knuckles, or any knife, dagger, dirk, or other similar weapon that is capable of causing death or bodily injury and is commonly used with the intent to cause death or bodily injury.

For the purpose of the restrictions on weapons in other specified areas, "weapon" means any firearm, explosive, or any weapon of the kind usually known as a slungshot, sand club, metal knuckles, or spring blade knife, or any dagger, dirk, pistol, or other dangerous weapon.

Restricted Areas.
It is unlawful for any person to enter the following places when he or she knowingly possesses or knowingly has under his or her control a weapon:

• the premises of a library established or maintained pursuant to Washington law;
• the premises of a zoo or aquarium accredited or certified by the Association of Zoos and Aquariums or the Zoological Association of America, or a facility with a current signed memorandum of participation with an Association of Zoos and Aquariums species survival plan; or
• the premises of a transit station or transit facility, including all passenger facilities, structures, stops, shelters, bus zones, and other properties that are owned, leased, held, or used by a transit authority for the purpose of providing public transportation services.

Exceptions.

The foregoing restrictions on weapons in libraries, zoos, aquariums, transit stations, and transit facilities do not apply to: 

• any person licensed to carry a concealed firearm pursuant to Washington law;
• law enforcement personnel;
• security personnel while engaged in official duties;
• correctional personnel or community corrections officers, as long as they are employed as such, and have completed government-sponsored law enforcement firearms training;
• any person engaged in military activities sponsored by the federal or state governments, while engaged in official duties; or
• the activities of color guards and honor guards affiliated with the United States military, Washington State National Guard, or Washington Department of Veterans' Affairs related to burial or interment ceremonies including, but not limited to, any staging and logistical requirements of the color guard or honor guard. 

The restrictions on weapons in zoos and aquariums also do not apply to employees of a zoo, aquarium, or animal sanctuary, while engaged in their employment, if the weapon is owned by the zoo, aquarium, or animal sanctuary and maintained for the purpose of protecting its employees, animals, or the visiting public. 

Definitions.
"Transit authority" means a city transit system, a county public transportation authority, a metropolitan municipal corporation transit system, a public transportation benefit area, an unincorporated transportation benefit area, a regional transit authority, or any special purpose district formed to operate a public transportation system.