Authorities in New Mexico say the teenager accused of murdering his parents and three younger siblings last weekend was "involved heavily" with violent video games. News reports quoted the sheriff of Bernalillo County saying the young man became excited during interrogations when he began discussing his love of games such as "Modern Warfare."

This connection is certainly not enough to explain all the reasons a young man would commit such an awful crime, or why he would then text a photo of his dead mother to his 12-year-old girlfriend. Certainly, not all who play such games commit crimes.

But it would be foolish not to notice how violent video games are a common denominator in many crimes such as these. The assailants in Newtown, Conn., and even at Columbine High School enjoyed participatory mock violence on the computer.

And it would be more than foolish to ignore mounting scientific evidence that exposure to violent video games has real effects on children.

Utah Rep. Jim Matheson has been somewhat of a lone wolf in the fight to impose tough guidelines on the sale of these games. For several years now, he has introduced a bill that would require stores to post the industry's own ratings system in a place where customers can see, and that would require customers to show identification and fine stores for selling an adult-rated game to a minor.

We applaud his efforts, which would provide some protection for impressionable children, for whom over-exposure to violence can lead to violent behavior of their own.

That assessment was made clear by the American Psychological Association, which in 2010 issued a statement that said the bulk of studies on the subject show clear evidence that exposure to media violence is a significant risk factor for aggressive and violent behavior.

Research shows these games may have even stronger effects than violence on television or in movies because of their interactive nature, as well as the way they tend to reward violent behavior and repeat such experiences over and over. Hands-on involvement, rewards and repetition can be powerful learning tools.

Matheson's efforts have largely been ignored because conventional wisdom says the U.S. Supreme Court already has outlawed bans on such games. What often gets lost in discussions about that 2011 decision, which struck down a ban on the sale of violent games to children in California, is that Justice Samuel Alito wrote a nuanced consenting opinion, signed by Chief Justice John Roberts, that called the law "well-intentioned" and left the door open for a better worded, more focused law.

Lawmakers' focus, then, should be on crafting a bill that would pass judicial muster, rather than ignoring the issue entirely. It would be wrong to focus solely on gun legislation (another solution that raises constitutional concerns), without also focusing on games that serve as a rare common thread in many of these crimes.