The suspect in the Buffalo supermarket massacre purchased the primary weapon allegedly used in the shooting — a used Bushmaster XM-15 semiautomatic rifle — from a licensed dealer near his hometown but said he then illegally modified the gun so he could use a high-capacity magazine.
He also recounted how he acquired two backup weapons: a Mossberg 500 shotgun that he purchased in early December and a Savage Axis XP bolt-action rifle that he received from his father as a Christmas present when he was 16 years old.
Gendron was arrested Saturday and charged with murder after police said he killed 10 people and wounded three others in a shooting spree at a Tops Friendly Markets store in Buffalo. Authorities said that the attack was racially motivated and that Gendron targeted the store because it was in a predominantly Black neighborhood.
The owner of Vintage Firearms, 75-year-old Robert Donald, confirmed to the New York Times and ABC News on Sunday that he sold the Bushmaster to Gendron. He said a background check raised no flags and that agents from the Bureau of Alcohol, Tobacco and Firearms visited his shop — an old one-room house — on Saturday night to collect paperwork from the sale.
“I happened to have this particular gun at this particular time,” Donald told ABC. “And this particular guy happened to buy it. After the gun leaves the firearm shop, you have no control.”
In New York state, customers ages 18 and older are allowed to buy rifles and shotguns without a permit, though they need to pass an instant criminal background check at the time of the sale. (Gun-control laws are more restrictive in New York City.)
Gun-purchase background checks are supposed to flag individuals with a history of mental illness but usually prohibit sales only to people in severe cases, such as people who have been institutionalized by a judge. Law enforcement officials said they investigated Gendron last June after he allegedly made a threatening statement. Buffalo Police Commissioner Joseph Gramaglia said New York state police took Gendron, then 17, into custody and transferred him to a hospital for a mental health evaluation. He was released a day and a half later.
In 2013, the state of New York passed a law banning the sale of assault-style semiautomatic rifles with 10 common features, including protruding pistol grips, flash suppressors, and folding or telescoping stocks. One of the suspect’s online postings includes a photo of his Bushmaster XM-15 E2S Target rifle with what appeared to be a pistol grip. He did not specify whether he purchased the rifle that way or whether he added the grip later.
In one posting, Gendron admitted to illegally modifying the weapon in another way. He wrote that he used his father’s power drill to remove a state-mandated lock that prevented the attachment of magazines with more than 10 rounds of ammunition.
New York state law bans the use of high-capacity magazines with more than 10 rounds. Gendron wrote that he wanted to use 30-round magazines during the massacre so he didn’t have to reload frequently.
In one posting, Gendron referred eight times to New York’s gun laws or those who obey them as “cuck” or “cucked,” a misogynist slur popular among some far-right extremists.
"Since I live in New York, I had to buy a cucked version of this before illegally modifying it,’’ Gendron wrote. “Since I live in cucked New York, and I am only 18, I can’t legally buy a lower or a standard ‘assault rifle.’” He added that he “could’ve even bought a NY-safe featureless rifle, but what kind of cuck does that?”
According to the Giffords Law Center to Prevent Gun Violence, eight states and the District of Columbia have banned “large capacity ammunition magazines” for both rifles and handguns. The laws in the District and most of those states — California, Connecticut, Maryland, Massachusetts, New Jersey, New York and Vermont — limit the number of allowable rounds to 10. Colorado authorizes 15 rounds for all firearms; Vermont allows 15 for handguns.
In a detailed and often-rambling explanation of his weapons and gear, the suspect wrote that he deliberately loaded heavier rounds to use in an initial volley to penetrate glass at the front of the supermarket where he expected a security guard would be keeping watch. He then loaded lighter rounds deeper in the magazine so he could use them to target shoppers and other victims in the store. Lighter bullets travel faster and can tumble through bodies more easily, causing maximum damage as they yaw through flesh.
A semiautomatic rifle can fire as fast as the shooter can pull the trigger. In a live-streamed video that the suspect posted online, he shoots his first victims quickly outside before moving into the store to fire on others, appearing to empty his magazine after about 30 shots. The entire sequence, from initial shots to the reload, is about 20 seconds.
The Bushmaster family of rifles is part of the ubiquitous family of AR-15 style weapons — the most common rifle in the United States. Used Bushmaster XM-15s can be bought for about $1,000 or less, putting it on the lower end of some AR-15 models that sell for hundreds more. The rifle is a no-frills option that lacks a rail system, which limits accessories like optics, lasers and forward grips. The alleged shooter complained there was no way to attach a light other than duct-taping one to the hand guard.
The Bushmaster XM-15 is the same model rifle that was used in two other notorious mass shootings: the 2002 D.C. sniper case, in which two gunmen killed 10 people at random during a month-long spree of terror in the Washington region; and the 2012 massacre at Sandy Hook Elementary School in Newtown Square, Conn., during which a lone gunman killed 20 first-graders and six staff members.
In February, the families of nine victims from the Sandy Hook massacre settled a lawsuit against Remington Arms, the manufacturer of the Bushmaster, for $73 million. Federal law makes it difficult to sue gun manufacturers for product liability. But the plaintiffs used a novel legal strategy, arguing under Connecticut law that the Bushmaster was tantamount to a weapon of war and that Remington improperly marketed the rifles to civilian men.
In one of his postings, the suspect offered a mixed appraisal of the Bushmaster XM-15 he had purchased. While said he selected the rifle for its lethality, he complained that its 20-inch barrel was too long and unwieldy. “This is literally the worst option for me since I will be mainly indoors and in my car.” He said he would bring the Mossberg shotgun and the Savage Axis XP rifle mainly as backup.
When Buffalo police arrested Gendron, they said, he was carrying a semiautomatic rifle that matched the description of the Bushmaster. The other two guns were recovered from his car.
A previous version of this article incorrectly described the Savage Axis XP rifle as semiautomatic. It is bolt-action. The article has been corrected.
Jon Swaine, Reis Thebault and Alice Crites contributed to this report.