DENVER - County sheriffs from across the state are trying to bring down two gun control measures signed into law in March with a constitutional challenge filed Friday in the U.S. District Court in Denver.

"Today represents a line in the sand," El Paso County Sheriff Terry Maketa said. "The filing of this lawsuit is our only option. We did not want this. We did not ask for this, but we will not stand by silently while good citizens are deprived of their rights and criminalized."

Maketa is among 54 sheriffs challenging the constitutionality of the state's ban on high-capacity magazines and the mandate that universal background checks be conducted on all gun sales, including between private individuals.

Those laws - HB 1224 and HB 1229 respectively - take effect in July and attorney David Kopel with the Independence Institute said the plaintiffs are considering asking for a temporary injunction to keep the laws from impacting gun-owning Coloradans.

Attorney General John Suthers released a statement that his office has worked with law enforcement to clearly outline how the laws are to be implemented with regard to issues raised with the legislation. Suthers will be responsible for mounting the legal defense on the state's behalf.

"The objective of the Attorney General's Office will be to get court rulings on the legality of various aspects of the legislation as expeditiously as possible," Suthers said in a statement. "Colorado citizens and law-abiding gun owners in particular, deserve such clarification."

Still, the lawsuit is expected to draw out for a long time. On the side of the sheriff's, it's being funded by donations accepted by the Independence Institute - a Denver-based think tank. The state's defense will be funded by taxpayers.

Sen. Mary Hodge, D-Brighton, who authored the magazine limit bill, said both laws were carefully written to be within constitutional bounds.

"They were constructed to protect us from massacres like the ones we suffered in Aurora and Newtown," Hodge said in a statement. "Reasonable Coloradans know that one doesn't need a large-capacity magazine for self defense."

Kopel said that the law requiring background checks for the sale or transfer of a firearm between individuals is so vague it violates the due process clause of the 14th Amendment.

And the process of obtaining a background check at a federally licensed firearm dealer is so burdensome that it violates the Second Amendment right to bear arms, he said.

The argument is more clear cut when it comes to the ban on the sale or possession of magazines that hold more than 15 bullets or tubes that hold more than eight shotgun shells.

Kopel said similar to handgun bans that were struck down by the U.S. Supreme Court in Chicago and Washington D.C., the ban on magazines overreaches a reasonable limit on the Second Amendment.

"What the Supreme Court said is you may not prohibit arms which are typically owned by law abiding persons for lawful purposes, so if you've got arms that are in that category, that includes magazines, that's the end of the case, in our view," Kopel said. "At the same time the court said you can ban things that are the opposite."

Kopel used the example of sawed off shotguns which are illegal at the federal level and machine guns that can only be owned with extremely tight permitting process.

"A pistol with a 17 round magazine is not some dangerous or unusual weapons that is only used by gangsters or terrorists or nuts," Kopel said. "It is a very good choice for a law abiding citizen for lawful protection."

However, magazines are not firearms, they are for many guns accessories that can be changed and selected to fit within a law.

Advocates say the laws are a reasonable way to not only prevent gun homicides but also massacres such as the Aurora theater shooting last summer.

Democrats argued during the legislative session that high-capacity magazines are weapons of war that have no place in neighborhoods, on streets or in movie theaters.


Contact Megan Schrader: 719-286-0644 Twitter @CapitolSchrader