By Brad Polumbo writing for Newsweek
From the article,
Their idea is simple: Raise the age to buy a gun to 21. Most school shooters are teenagers, the argument goes, and you can't drink alcohol until age 21, so why can you buy an AR-15? But there are a few big reasons why this proposal is unrealistic, impractical, and ultimately unlikely to accomplish anything. First, any law uniformly raising the age to buy a gun to 21 would face immediate constitutional challenges and likely be stuck down as a violation of the Second Amendment. The age of legal adulthood is still 18. Further, it wouldn't be particularly difficult for a determined killer to simply have someone purchase a firearm for them (like every teenager in America has done for booze). Unfortunately, that's exactly what happened in the Columbine shootings. The killers were both under 18, yet simply had someone older buy the guns they used. In many other school shootings, the killers stole the guns from an older family member.