A political action committee supporting Mike Johnston's run to be the Democratic nominee for Colorado Governor has a new political ad.

The 30-second television spot produced by Frontier Fairness PAC is entitled "Courage" and uses Johnston's own words from a gun safety town hall he held at North High School on March 14.

CLAIM: "Columbine, when it happened was the worst school shooting in American history. Today, it doesn't rank in the top 10."

VERDICT: Not true

First, let us state that we're not here to nitpick and give you a Family Feud-style top 10 list of worst school shootings. A Truth Test is to provide facts and context, and keep politicians and political action committees honest, so you can make an accurate and thoughtful decision with your vote.

9Wants To Know investigative reporter Chris Vanderveen and producer Katie Wilcox detailed the history of school shootings in March, and have updated that database since the school shooting in Santa Fe, TX earlier this month.

On April 20, 1999, 12 students and a teacher were killed at Columbine. Prior to that, 44 died when a man planted dynamite at a school in Bath, MI in 1927. In 1966, 16 died when a former Marine opened fire from a clocktower at the University of Texas.

Since Columbine, three modern school shootings have resulted in more families finding out the worst news. The shootings at Virginia Tech, Sandy Hook and Marjory Stoneman Douglas have all resulted in higher fatalities than Columbine.

According to a spokeswoman for Frontier Fairness PAC, Johnston "pivoted" to mass shootings in the second part of his statement.

Frontier Fairness PAC used this CNN article as supporting backup for the statement that Johnston made at the town hall. If you consider mass shootings that happened outside of schools, then yes, Columbine is no longer in the top 10. However, it is not clear that is the reference Johnston is making in his statement.

The ad continues with text on screen showing "Johnston's Plan," showing the following:

-Ban military-style weapons

-Create gun-violence restraining orders

-Ban bump stocks

-Background checks on all gun sales

CLAIM: Johnston Plan: Background Checks on All Gun Sales

VERDICT: Misleading

It is misleading for Frontier Fairness PAC to say this is part of "Johnston's Plan" since it is already the law in Colorado.

In 2013, the Colorado legislature passed a bill, signed by Gov. John Hickenlooper, that requires background checks for all gun sales.

In fact, as a State Senator, Johnston voted in favor of the bill when it ultimately made it out of the Senate on Mar. 15, 2013. The bill was on the Governor's desk on Mar. 19, 2013 and signed by Hickenlooper the next day.

It does have exceptions for gun transfers, but it requires background checks for all gun sales, including private person-to-person sales.

9NEWS asked Frontier Fairness PAC for the raw video of Johnston's town hall that was used to create this ad, but we were told no raw video was available. We did not contact Johnston or his campaign since this is not an ad produced by the campaign.