The Colorado Bureau of Investigation does background checks for gun purchases and assists sheriff departments with concealed gun permits by running fingerprints.

CBI's spokeswoman Susan Medina said there is no database for firearm purchases in Colorado.

Medina said federal and state laws say the CBI is required to destroy a record of approval within 24 hours of that transaction.

If the person is not approved to purchase a gun, the CBI will keep the record if the person appeals for a period of time.

In Colorado, if you're at a gun show and there is a private sale, the seller has to do a background check. If a neighbor is selling to a neighbor, the check is not required, but possible through the CBI online background check.

Local sheriff's departments issue conceal and carry permits. There is no uniform way each department tracks those. The number of permits issued is eventually provided to the state, but it had no private information.

"Right now we've got a system that I think works pretty well but still would that stop somebody from going out and getting a weapon illegally? No, not a bit," said Christopher H. Olson, Executive Director of County Sheriff's of Colorado.

Every state can have their own laws when it comes to keeping track of guns and who owns them.

According to the Bureau of Alcohol, Tobacco and Firearms, it can't keep a national registry of certain firearms, including rifles, shot guns, pistols and revolvers. It was prohibited by Congress, said Bradley Beyersdorf, ATF spokesman.

When the law was written, there was concern that someone will use the list to go after people and take their guns away. Different states have different laws about conceal and carry, Beyersdorf said.

In 1934 National Fire arms act requires people to register their machine guns and short barrels shot guns. But the ATF -the keeper of the record, is prohibited from releasing that information, as it's considered tax records.