Background Checks for Firearms Transfers.
Certain categories of persons are disqualified from possessing firearms under state and federal law.  This includes any person who has been convicted as an adult, or adjudicated as a juvenile, of a felony offense or certain domestic violence misdemeanor offenses.  In addition, persons who have been involuntarily committed for mental health treatment or competency restoration, or who have certain other mental health related adjudications, are prohibited from possessing firearms under both state and federal law. 
 
Under federal law, a dealer must, with few exceptions, conduct a background check on all firearms transfers through the National Instant Criminal Background Check System (NICS).  Under state law, a state background check in addition to the federal NICS background check is required for the purchase or transfer of a pistol or semiautomatic assault rifle.  The state background check must be conducted by the local law enforcement agency, or the state once a state background check system is established.
 
Bipartisan Safer Communities Act.
The federal Bipartisan Safer Communities Act (BSCA), enacted in 2022, specifically provides that federal firearms prohibitions apply if the person's juvenile record includes a prohibiting criminal conviction or involuntary commitment or mental health adjudication.  In addition, the BSCA established new provisions relating to background checks for persons under the age of 21.  The NICS must contact state and local authorities to determine whether the individual has juvenile criminal or mental health records that would disqualify the person from purchasing a firearm.  Mental health history records may only be accessed from the time the person turned 16.  This enhanced background check requirement for persons under the age of 21 expires automatically after 10 years if not renewed.
 
Sealing of Juvenile Records.
Records of juvenile offense adjudications are public unless sealed.  A juvenile offense record may be sealed through a regularly held administrative hearing or by filing a motion with the court.  Once a juvenile record is sealed, the proceedings in the case must be treated as if they never occurred.  With limited exceptions, once a juvenile record is sealed, files and records included in the sealing order may be inspected only by order of the court upon a motion made by the subject of the information of complaint. 

Any subsequent juvenile adjudication or filing of an adult felony charge unseals the case.  The Administrative Office of the Courts must ensure prosecutors have access to information on the existence of sealed juvenile records.  In addition, the Washington State Patrol (WSP) must provide Washington criminal justice agencies with access to sealed juvenile records information through the Washington State Identification System (WASIS).  The WSP is not authorized to share this information through WASIS with criminal justice agencies outside of Washington.  Criminal justice agencies are prohibited from disclosing confidential information or sealed records accessed through the WASIS or other means.

The WSP must ensure that non-Washington criminal justice agencies have access to sealed juvenile records only for the purpose of conducting a background check for processing and purchasing firearms, concealed pistol licenses, and alien firearms licenses, and releasing of firearms from evidence.

Non-Washington criminal justice agencies that access sealed juvenile records for firearms-related purposes must not knowingly disseminate the accessed records or information in the records to a third party.  Dissemination of such records or information subjects the disseminating agency to the jurisdiction of Washington courts and a civil penalty of not more than $1,000 per violation.