美国广播公司新闻获得的一份在线文件似乎记录了佩顿·詹德龙在据称他被杀害前至少两个月是如何精心策划袭击的开枪打死了10个人据执法部门消息，在水牛城的一个友好市场。
根据这份文件，詹德龙在3月8日开车去了布法罗，参观了这家超市，在那里他被一名商店的保安询问，当时他正在编制该地点的详细计划。
这份589页的文件与詹德龙据称在大屠杀前发布在网上的180页充满仇恨的长篇大论是分开的，其中包括超市的草图，包括不同过道的构成，以及如何快速浏览的说明。
执法官员正在调查这份文件的来源和真实性，试图确定谁可能接触过它。
消息人士告诉ABC新闻，该文件是从2021年开始发布到在线社区平台Discord的消息汇编。
据最先报道该文件的《华盛顿邮报》报道，该文件于4月29日由一名匿名用户上传至文件共享网站MediaFire，并可在周一之前访问。帖子称，在帖子联系该平台进行评论后不久，该文件被删除。
据熟悉电话的消息人士称，在周二与州和地方合作伙伴的电话会议上，执法官员表示，Gendron在2021年夏天开始发布关于防弹衣的不和谐帖子。通话中的官员说，2022年4月，螺纹还嘲笑联邦执法部门。
美国广播公司新闻顾问、前国土安全部官员约翰·科恩表示，高中学生和游戏玩家通常会使用Discord。
科恩说:“由于聊天群的创建者对内容拥有控制权，它也越来越成为暴力极端分子的首选平台。”
目前还不清楚是谁(如果有的话)接触到了这些帖子。
这份文件详细描述了詹德龙在3月份去超市时与他描述的一名黑人武装保安的互动。
据权威人士称，一名保安被杀在周六的袭击中，在向有防弹衣保护的詹德龙开火后。
另一个帖子将Tops超市描述为第一个目标位置接着列出了附近另外两个可能被袭击的地点，包括一家熟食店和一家理发店。
在美国广播公司新闻频道(ABC News)获得的纽约警察局(New York Police Department)周一发布的一份公告中，官员们表示，这种在线交流“强调，通过社交媒体、在线游戏平台或4chan等匿名留言板与极端主义文化和意识形态的在线联系，在动员个人参与暴力方面，可能与与与现实世界团体的联系一样有效。”
“在线游戏平台，特别是Twitch和Discord，由于内容适度性最低，已经成为极右翼极端分子的热门社交媒体替代品，而不是更主流的社交媒体平台，”NYPD公报说。
密歇根州立大学刑事司法学院(School of Criminal Justice)院长兼教授托马斯·霍尔特(Thomas Holt)告诉美国广播公司新闻(ABC News)，这些平台的内容“随着时间的推移发生了变化”，“一些团体比其他团体更加激进。”
霍尔特说，一些极端主义用户更喜欢这些平台，因为管理内容的规则留给了个人版主。
霍尔特说:“在这些论坛上，你可以随心所欲地采取行动，这取决于版块或整个网站的版主采取行动——这是高度可变的。”。
Document appears to show Buffalo shooter's planning including March trip to supermarket
An online document obtained by ABC News appears to chronicle how Payton Gendron carefully planned out his attack at least two months before he allegedlyshot and killed 10 peopleat a Tops Friendly Market in Buffalo, according to law enforcement sources.
According to the document, Gendron, on March 8, drove to Buffalo and visited the supermarket, where he was questioned by a security guard at the store as he was compiling detailed plans of the location.
The 589-page document, which is separate from the 180-page hate-filled screed Gendron is alleged to have posted online just before the massacre, includes sketches of the supermarket, including the makeup of different aisles, with notes on how to navigate around quickly.
Law enforcement officials are investigating the document's origins and authenticity as they try to determine who may have had access to it.
Sources tell ABC News that the document is a compilation of messages posted to the online community platform Discord starting in 2021.
According to the Washington Post, which was first to report on the document, it was uploaded to the file-sharing site MediaFire by an anonymous user on April 29, and was accessible until Monday. The document was deleted shortly after the Post contacted the platform for comment, the Post said.
On a conference call Tuesday with state and local partners, law enforcement officials said that Gendron began posting threads to Discord regarding body armor in the summer of 2021, according to a source familiar with the phone call. In April of 2022, the threads also taunted federal law enforcement, officials on the call said.
ABC News Consultant and former Department of Homeland Security official John Cohen said Discord is commonly used by high school kids and gamers.
"Because the creator of a chat group has control over content, it has also increasingly become a platform of choice for violent extremists," Cohen said.
It is unclear who, if anyone, had access to these posts.
The document details Gendron's interactions with what he describes as a black armed security guard during his March visit to the supermarket.
According to authorities, asecurity guard was killedduring Saturday's attack after firing at Gendron, who was protected by body armor.
Another post describes the Tops supermarket as thefirst location to be targeted, and goes on to list two other nearby locations to possibly attack, including a deli and a barbershop.
In a bulletin published Monday by the New York Police Department and obtained by ABC News, officials said this type of online communication "underscores that an online connection to an extremist culture and ideology through social media, online gaming platforms, or anonymous message boards like 4chan, can be equally effective in mobilizing individuals to violence as connections to real-world groups."
"Online gaming platforms, in particular Twitch and Discord, have become popular social media alternatives for far-right extremists due to minimal content moderation, as opposed to more mainstream social media platforms," the NYPD bulletin said.
Thomas Holt, director and professor in the School of Criminal Justice at Michigan State University, told ABC News that the content in these platforms has "changed over time" and that "some groups have radicalized more than others."
Some extremist users prefer the platforms because the rules governing content are left to individual moderators, said Holt.
"In these forums you can kind of act as you wish, and it just depends on the moderators of either the subsection or the overall site to take action -- and that's highly variable," Holt said.
