In a comment on my Jan. 9 illustration about gun violence and politics, reader "Matt" wanted more information on a statistic I used: 85 percent of children who die by gunfire on the planet are killed in the United States.

"I think this is a complete false accusation and would like to see your facts on this or where you are citing this from," he wrote. "Telling lies is not my idea of unbiased journalism, and I would ask that you research your statements before making them, especially if you are a public entity paid for with my tax dollars."

Thanks, Matt, for taking the time to check out my drawing and to comment on it. 

I cited something that I heard Mark Kelly, Gabrielle Giffords' husband, tell ABC News. Watch the video above. I failed to cite my source, which was a mistake. Perhaps Kelly was taking into account more wide-ranging studies that I have not been able to find.

Here is the report by ABC News, which cites a number of studies, one of which compares gun deaths in general, and gun deaths of children in America, with gun deaths in the 22 other richest countries in the world — our peers. These numbers are very close, and slightly worse than the ones I noted while watching his interview with Dianne Sawyer.