To purchase a gun in Germany, you must earn — usually over the course of several months — a certificate that proves you know how to handle both the weapon and its ammunition. You must prove that you can store it safely, in a place to which only you, as the owner, have access. You cannot acquire any shooting weapon until you are at least 18, and if you are under 25 you must undergo a psychological exam before being allowed to own a gun.

Even marksmen or hunters with decades of experience must register each new gun they purchase.

Oversight for all this is with the Weapons Authority, which is part of the Criminal Office (the investigative branch of the police) that exists in each of the 16 states. The Weapons Authority can carry out random inspections at the homes of gun owners.

Crimes involving guns are still relatively rare. German government statistics showed that while criminal acts increased last year to just over six million in a country of 80.6 million people, crimes that violated weapons laws declined to 30,785 cases, or by 2.1 percent, from 2013.

There was a slight decrease in violent crimes last year in the United States as well, and the rate of gun-related homicides declined to 3.6 per 100,000 people by 2010 from 6.6 per 100,000 in 1981. But the Gun Violence Archive, a nonprofit group that keeps track of gun violence, tallied more than 40,000 acts of violence involving guns so far this year.

Mr. Lach, who has been shooting for 40 years, is among the hundreds of thousands of sports shooters in Germany who tend to meet in tradition-laced clubs to pursue their hobby. These marksmen, and equally enthusiastic hunters, make up the bulk of gun owners.