Another month, another record number of murders in Mexico. For the first nine months of 2019, Mexico had 25,890 murders—almost six times as many murders per 100,000 people as in the U.S. Does Mexico need stricter gun control?

No. Its gun laws are among the least permissive in the world. For decades Mexico has had only one gun store in the entire country, a military-run establishment in Mexico City. The store’s prices are very expensive, and the most powerful rifle that you can buy there is a .22 caliber. There’s no “gun-show...