A Missouri judge has ruled that requiring St. Louis County to issue concealed pistol licenses (CPLs) to its residents would impose an unconstitutional cost on the county government, according to Associated Press.

St. Louis County, home to nearly one of every five Missourians, filed suit after the state Supreme Court in February upheld the legislature’s right to legalize concealed guns, but found the law’s funding mechanism could be illegal in certain instances.

The law, adopted last year, allows law-abiding Missourians age 23 and older to receive CPLs from their county sheriffs after passing criminal background checks, a firearms training course and paying a fee.

Jackson County, St. Louis County and the city of St. Louis have refused to accept CPL applications. Jackson County was spared from doing so by the Supreme Court ruling; St. Louis has simply refused to issue permits.

Cole County Circuit Judge Thomas Brown ruled on St. Louis County’s case on Oct. 8.

County Executive Charlie Dooley called the court ruling a significant victory. Attorney General Jay Nixon, whose office defended the law, said on Oct. 12 he was considering an appeal.

The fee required for someone to get a concealed gun permit has been the focus of the legal challenges.

The Supreme Court said the law does not allow the fee to cover anything beyond equipment and training. That prevents it, for example, from being used to cover the $38 cost of getting a fingerprint background check.

By requiring new duties without supplying money, the state imposed an illegal unfunded mandate under the state constitution, the high court ruled in February.

But the Supreme Court said the unfunded costs had to be proven for a county to be exempt from enforcing the law. Brown’s ruling confirmed those costs existed in St. Louis County.

Most Missouri sheriffs have issued permits while finding ways to reduce their costs.