COLORADO SPRINGS, Colo. - It was so controversial that it cost several state lawmakers their seats, but three and a half years after it passed, less than two dozen people have been convicted of a Colorado gun control law passed in 2013.
The law requires background checks on all private sales of firearms, separate from purchases at gun stores and gun shows.
Justin Mills is among the convictees.
In October of 2013, Mills was arrested downtown for Disorderly Conduct, Prohibited Use of Weapons, and Obstructing a Peace Officer.
Mills later admitted he had bought his Glock 19 from another man three days earlier without undergoing a background check required, making him one of the first to be charged under the new law that went into effect July 1.
A KRDO Newschannel 13 open records investigation found as of January 2016, he is one of only 18 people in the entire state convicted under the new statute.
David Kopel, Research Director of the Independence Institute, notes that the extra charge was hardly consequential in each case.
"It's ok to have add-on charges, but these people would have already been prosecuted under the larger criminal offense that got police involved in the first place," he points out.
Kopel, as well as republican State Senator Kevin Lundberg of Berthoud, say the lack of prosecution confirms their prediction that the law by itself would be virtually unenforceable.
"In a private sale, you are sorely tempting everybody to ignore the law, which I'm certain occurs," said Lundberg.
However, democrats who supported the bill say the number of cases prosecuted doesn't tell the whole story.
They say the law was never about punishing people for violating it.
John Morse, a former democratic state senator from Colorado Springs, explains, "We don't measure how effective the law forbidding homicides is by the number of people we prosecute under that statute. We measure it more by the number of homicides we prevented."
Another former lawmaker, Beth McCann, who worked alongside Morse to get the law passed, added, "The goal of the legislation was really to prevent these sales."
Morse and McCann instead point to the number of background check denials in private sales as a measure of its impact.
An investigation into years of Colorado Bureau of Investigation records found just over 1200 denials from private sale background checks since the law went into effect.
"And the reason those have been prevented is because the person trying to purchase the gun had a felony conviction, or had a domestic violence temporary restraining order or restriction, or was a fugitive. So these are the people that we don't want to have guns," said McCann.
But critics argue the 1204 denials aren't an accurate indicator.
According to CBI data, roughly 40 percent of the denials are connected to background checks at gun shows, which were already required by a separate law passed in 2000.
Also, background checks aren't always accurate, according to Kopel and Lundberg.
"Colorado has the highest rate in the country of false denials and the highest rate of reversal of false denials," said Kopel.
Lundberg adds, "When we use background checks and somebody is denied, if it's for a reason that isn't legitimate, then we have denied that person their constitutional rights."
Tune in Wednesday night as current and former lawmakers rate the overall success of the law, and find out whether opponents have ended their legal and legislative efforts to get rid of it.
If you missed Part 1 of our special report, you can watch it here.