SPOKANE COUNTY, Wash. — Spokane County Sheriff Ozzie Knezovich called I-1639 — a Washington law that raises the minimum age to purchase a semi-automatic rife to 21, among other things — unconstitutional in a Facebook post on Thursday.

In a thread on the SCSO Facebook page, Knezovich was asked his stance on I-1639 and if he planned on enforcing the law or not. Knezovich said that other sheriffs are "grandstanding" by not supporting it.

"These other sheriffs are purely grandstanding when they say they won't enforce 1639 because there is nothing for us to enforce," he wrote in a response.

Knezovich cited the fact that he thinks the law is being challenged in court and his belief that it is unconstitutional as the reasons why there "is nothing for me to enforce."

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On Thursday, Sheriffs from Adams and Benton counties also said they would not be enforcing the law. They joined the Lewis County Sheriff's Office and Republic Police Chief Loren Culp in saying they will not enforce the law.

I-1639 calls for enhanced background checks and established a requirement forcing gun buyers to complete a firearm safety course in addition to raising the minimum age requirement for buying a semi-automatic rifle from 18 to 21. The initiative was passed in last November's election.

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Knezovich also wrote that the law "is unconstitutional at the state and federal level," in a response on the post. He also said he had offered to join in a lawsuit against the intiative but that lawyers "aren't sure how to add me in the lawsuit since Sheriff's [sic] have no skin in this one."

In addition to calling himself a strong 2nd Amendment supporter, Knezovich also said I-1639 should not have become law and is "not about school safety or protection."

RELATED: NRA suing to block Initiative 1639