德州教堂枪杀案凶手的武器：AR-15式步枪

The shooter in a Texas church that killed 26 people Sunday used a Ruger AR-556, which is a variant of the AR-15 rifle — the most popular rifle in America.

Various versions of the AR-15 rifle have been used in some of America's most deadly mass shootings, including the Orlando nightclub shooting in 2016 that killed 49 people and the Las Vegas shooting last month that killed 58 people.

The AR-15 is trademarked by the Colt company, though other manufacturers market similar rifles under different brand names, like the AR-556 used by the church shooter. The 556 in the rifle's name is a reference to the 5.56 millimeter ammunition it uses.

AR-15s are sometimes called assault rifles, though this is incorrect because assault weapons are fully automatic machine guns and have been heavily regulated in the U.S. for more than 80 years.

The AR-15 was first developed in the 1950s and was eventually modified and adopted by the military and renamed the M16. The military version is fully automatic, meaning it will keep firing as long as the trigger is pressed. The AR-16 available for civilians is "semi-automatic," meaning the trigger must be pulled each time the weapon fires a round.

The guns are popular in America due to their reliability and their relatively low price tag. The Ruger AR-556, for example, has a retail price under $800. The guns can be outfitted with customized stocks, barrels, scopes and other accessories.

The National Shooting Sports Foundation (NSSF) says there are between five and 10 million AR-15 rifles legally owned in the U.S., which represents a small fraction of the roughly 300 million total firearms owned by Americans.

FBI data show that in the five years ending in 2017, the most recent data available, rifles, including the AR-15, were used in 2.4 percent of U.S. homicides; handguns, by comparison, were used in at least 48 percent.

周日德克萨斯州教堂枪杀血案凶手德文·凯利使用的是一支AR-556步枪。这种枪是美国最受欢迎的AR-15步枪的一个变种。

美国一些最严重的枪击案的凶手使用了AR-15的不同变种型号。这些血案包括2016年导致49人死亡的奥兰多夜总会枪击案和上个月发生的导致58人丧生的拉斯维加斯枪击案。

AR-15由柯尔特 (Colt) 公司注册商标，不过很多制造商使用不同的品牌推销同类步枪，比如德州教堂枪杀案凶手使用的是AR-556。556指的是该枪所用子弹口径为5.56毫米。

AR-15有时被称为攻击步枪，不过这种说法并不准确，因为攻击步枪是全自动武器，而美国对全自动枪已经有了80多年的严格监管历史。

AR-15最早在1950年代研发，后来被改装为军用，美军将其重新命名为M16。军用的M16为全自动步枪，也就是说，只要按住扳机，就可以连续发射。民间市场上的AR-16是半自动步枪，也就是说，每按一次扳机，只能发射一发子弹。

这类枪支在美国广受欢迎，这是因为它们的可靠性以及相对低廉的价格。比如说，儒格(Ruger)AR-556的零售价格不到800美元。这些枪可以装上定制的枪托、枪管、瞄准镜和其它附件。

美国“全国射击运动基金会”(NSSF)说，目前在美国有5百万到一千万支合法拥有的AR-15步枪，只占美国人所拥有的枪支总量的一小部分。美国人总共拥有大约3亿支枪。

根据可获取的联邦调查局的最近期数据，在截止2017年的五年期间，包括AR-15在内的步枪只占美国他杀案件所用凶器的2.4%。相比之下，手枪占所有谋杀案凶器的至少48%。