A San Francisco gun control law was upheld by the U.S. Supreme Court on Monday. The justices rejected a Second Amendment challenge by gun rights advocates. The activists were fighting a San Francisco gun regulation that mandates gun owners keep their firearms disabled or locked away while stored in their own homes. The San Francisco gun control regulation was approved in 2007.

The San Francisco gun law infringes on the Second Amendment and limits the ability of residents to defend themselves, gun rights activists maintain. An armed intruder is not likely to wait while a gun owner unlocks his or her gun. The court declined a request to hear an appeal filed by the National Rifle Association (NRA) and gun owners in the Jackson v. San Francisco, U.S. Supreme Court, No. 14-704 case. The refusal left intact a March, 2014, ruling by the San Francisco-based 9th U.S. Circuit Court of Appeals that upheld the gun control law.

Two of the nine-justice court’s conservative justices, Clarence Thomas and Antonin Scalia, reportedly said they would have taken the Second Amendment rights case. Justice Thomas said in a brief that the U.S. Supreme Court has detailed an approach to be used when dealing with right to bear arms cases to lower court. Thomas added that he feels that San Francisco has “failed to protect it [Second Amendment] in this case.”

Gun owners won an injunction which would have stopped what they strongly feel is an infringement upon the Second Amendment from being enacted, in 2012. The same appeals court also recently upheld a ban on hollow-point ammunition. Such ammo is designed to fragment, or expand, upon impact.

The U.S. Supreme Court has not agreed to hear a “major gun case” since 2010. One of the most recent Second Amendment cases heard by the high court was the District of Columbia v. Heller case in 2008. The ruling “clarified” the text of the Second Amendment in the Constitution and stated that individual Americans do indeed have the right to bear arms, and such rights are not limited to state militias. The justices struck down a Washington, D.C. regulation that also required trigger-locks on guns inside the home. In 2010, during the McDonald v. City of Chicago case, the court held that the earlier ruling applied to the states.

The U.S. Court of Appeals for the 9th Circuit ruled that the San Francisco gun regulation “did not pose an undue burden on Second Amendment rights.”