▶ Watch Video: Former FBI agent talks rise in gun violence and mass shootings Washington — The Justice Department on Wednesday asked a Missouri court to invalidate a new state law that prohibits state and local officials from enforcing federal firearms laws, arguing it violates the Constitution and has already done harm to public safety in the state. Federal prosecutors filed a statement of interest in a challenge to the Missouri law brought by St. Louis and Jackson Counties, which seeks to block enforcement of the measure. The Justice Department told the Cole County Circuit Court it supports a finding that the law, known as HB85, is unconstitutional and an order halting its enforcement. “HB85 has caused, and will continue to cause, significant harms to law enforcement within the state of Missouri,” the Biden administration wrote in its filing. “HB85 is also plainly unconstitutional.” Prosecutors warned the law has already hindered law enforcement efforts to promote public safety in the state and is undermining law enforcement activities, as it interrupts federal, state and local partnerships. Signed by Republican Governor Mike Parson in June, the measure at the center of the legal battle enacts a $50,000 fine on any law enforcement agency with officers who knowingly enforce federal firearms rules. Under the law, called the Second Amendment Preservation Act in Missouri, federal gun laws that fall into five categories are considered a violation of the Second Amendment and therefore not recognized by the state. While Democrats argued the Missouri law is unconstitutional, Republicans said it was meant to protect Missouri residents’ gun rights from attempts by the Biden administration to impose more stringent firearms restrictions. The Justice Department warned state officials in June that Missouri can’t ignore federal law, but Parson and Attorney General Eric Schmitt said they intended to still enforce the new law. In its filing with the Missouri court, the Justice Department warned the state’s law has already limited federal law enforcement’s access to “essential information” obtained through information-sharing networks such as the National Integrated Ballistic Information Network, which allows investigators to match ballistics evidence with other cases nationwide. Some jurisdictions have suggested they will limit data provided to the network because of the new state law. Prosecutors further argued that for private citizens and federal firearm licensees in Missouri, the law “creates confusion regarding the validity of federal firearm laws and federal enforcement authority.” “HB85’s repudiation of federal authority threatens to provoke erroneous beliefs about — and potentially opposition to — federal agents performing their law enforcement duties, including executing search warrants, making arrests, and seizing firearms used in crimes,” they told the Missouri court. The court is set to weigh the legality of the state’s new law in a hearing set for Thursday.