华盛顿大都会警察局的联邦探员和侦探对周三发生在美国国会大厦该消息来源告诉美国广播公司新闻，包括努力确定一个准军事派系的暴徒入侵美国政府的心脏的动机。

“我们正在谈论一项非常复杂的调查，”罗伯特·博伊斯说，他是一名35年的老兵，也是纽约警察局前侦探局长。

调查人员已经开始了展开和记录1月6日事件的艰巨任务，数千名支持特朗普的集会者穿过国家广场，越过国会警察的金属路障，闯入美国国会大厦神圣的大厅。在混乱中，有五人死亡，其中包括国会警察布莱恩·西克尼克。

调查人员告诉美国广播公司新闻，这项工作包括扫描大量社交媒体帖子，审查数小时的安全摄像头镜头，并梳理堆积如山的手机数据，以确定到底发生了什么。

司法部已经宣布逮捕了许多入侵者，包括一名张贴自己坐在众议院议长南希·佩洛西办公桌前照片的人。

博伊斯说:“自我认同的白痴将是第一个离开的人。”。

参与调查的消息人士告诉美国广播公司新闻，首要任务是确定是否有抗议者促成或导致了西克尼克的死亡。当局目前认为他的死亡是由医疗条件造成的，但他们也在积极审查关于他在国会大厦被灭火器或其他物品袭击的报告。到目前为止，关于袭击的报道还没有得到证实，当局希望找到现场的视频或其他图像，以了解发生了什么。

除了确定西克尼克是如何死亡的，调查人员还记录了导致警方枪杀一名35岁的圣地亚哥妇女阿什丽·伊丽莎白·巴比特的时刻。视频显示，巴比特在试图爬进议长大厅一扇门的破玻璃窗时被枪杀。

官员们面临一系列其他挑战。烟酒枪支管理局的调查人员确定，在民主党和共和党总部安放的炸弹是真正的装置。

炸弹技术人员用高压水枪炸开这些装置，从本质上来说是将它们拆开，使它们变得无害。消息人士称，调查人员正在检查回收的碎片，以寻找关于这些设备是如何建造的以及部件来源的线索。他们还公布了一张监视照片，照片上是一名穿着厚重斗篷的男子，他们认为是他放置了炸药。

国会警察周四表示:“这些设备被禁用，并移交给联邦调查局进行进一步调查和分析。”

另一项任务将是确定为什么录像显示一些入侵者穿着准军事装备在国会走廊游荡，带着拉链和行李袋，似乎有超越自拍或挥舞旗帜的目的。

两名熟悉调查的官员表示，执法部门不仅正在努力识别数百名暴徒，还在努力区分那些跟随暴徒的人，以及那些可能希望伤害副总统迈克·彭斯或国会领导人的人，他们聚集在一起完成2020年总统选举的认证。

执法官员告诉美国广播公司新闻，调查人员将使用手机数据来识别其手机从国会大厦内部发出信号的个人用户。

美国广播公司新闻(ABC News)国家安全分析师、前助理国防部长米克·马尔罗伊(Mick Mulroy)是一名退休的中情局官员和美国海军陆战队士兵，他说，他预计联邦调查局(FBI)将对所有参与袭击的人，特别是那些被捕的人，进行全面的反情报扫荡，以确定可能的外国情报联系。

“如果不太可能的话，包括俄罗斯在内的外国情报机构可能会秘密资助“骄傲的男孩”或“誓言守卫者”等组织，作为让美国人相互对立的秘密影响力运动的一部分，”穆尔罗伊说。“他们也有可能利用机会进入参议院或众议院中包含敏感信息的设施和办公室。”

司法部官员告诉记者，他们的目标是识别人，在某些情况下，以“占位性指控”逮捕他们，因为他们调查他们是如何来到国会大厦的，以及袭击涉及多少策划。科尔说，现在讨论任何外国行动的证据都为时过早。

除了正在进行的对参与国会大厦事件的人的指控进行整理的所有努力之外，国会领导人说，他们预计将进行单独的调查，以检查美国国会警察在动荡时期的行为。

随着如此多的调查线索被拉出来，联邦和地方当局一再强调，预计在未来几天、几周和几个月内会有更多的逮捕和指控。

美国联邦调查局(FBI)局长克里斯托弗·雷(Christopher Wray)周五表示:“今天的指控只是联邦调查局(FBI)持续努力追究1月6日美国国会大厦被盗期间发生的暴力和破坏犯罪行为责任的开始。”

与此同时，据报道，特朗普总统在离任前讨论了赦免自己的可能性，调查人员周五暗示他们是不太可能起诉反对那些被指控在周三早些时候在国家广场集会上煽动暴乱的人。集会上的发言人包括总统和他的几名家庭成员。

“我们不期待任何这种性质的指控，”一名司法部官员周五表示。

周五晚上，联邦调查局负责人助理局长史蒂文·安托诺(Steven M. D'Antuono)在一次新闻发布会上表示，对国会大厦入侵者的指控“只是联邦调查局和我们的合作伙伴在过去几天所做的大量工作的开始，我们远远没有完成。”

他补充说:“我们看到的暴乱和破坏是联邦调查局不会容忍的，我可以向你保证，联邦调查局华盛顿外地办事处和其他总部和外地办事处资源正在夜以继日地努力工作，调查那些对我们周三看到的暴力和犯罪行为负有责任的人。”

安托诺还警告了那些尚未被识别或逮捕的参与者:“仅仅因为你已经离开了华盛顿特区，如果我们发现你参与了国会大厦内的犯罪活动，你仍然可以期待有人敲门。一句话——联邦调查局在这次调查中不会放过任何资源。”

Investigators combing through massive US Capitol crime scene in wake of pro-Trump riot

Federal agents and detectives from the D.C. Metropolitan Police Department have launched a broad and multipronged investigation into the mayhem and death Wednesday at theUnited States Capitol, that sources tell ABC News includes an effort to determine the motives of a paramilitary faction of the mob that invaded the heart of American government.

"We're talking about a very complex investigation," said Robert Boyce, a 35-year veteran and former chief of detectives of the New York Police Department.

Investigators have begun the painstaking task of unwinding and documenting the events of Jan. 6, as thousands of pro-Trump rally-goers crossed the National Mall, overran Capitol Police metal barricades, and barged through the hallowed halls of the U.S. Capitol building. In the chaos, five people died, including Capitol Police officer Brian Sicknick.

That effort involves scanning volumes of social media posts, reviewing hours of security camera footage, and combing through mountains of cellphone data to determine exactly what occurred, investigators told ABC News.

Already, the Department of Justice has announced numerous arrests of intruders, including one who posted photos of himself seated at House Speaker Nancy Pelosi's desk.

"The idiots who self-identify will be the first to go," Boyce said.

A priority will be determining whether any protesters contributed or caused Sicknick's death, sources involved in the investigation told ABC News. Authorities currently believe that his death was driven by a medical condition, but they are also vigorously examining reports that he was attacked with a fire extinguisher or other item at the Capitol. So far, those reports of an attack have not been confirmed, and authorities are hoping to locate video or other imagery from the scene that can shed light on what occurred.

In addition to determining how Sicknick died, investigators are also documenting the moments that lead up to the fatal police shooting of a 35-year-old San Diego woman named Ashli Elizabeth Babbitt. Video shows Babbitt was shot as she was trying to crawl through a broken glass window in a door to the Speaker’s Lobby.

Officials face an array of other challenges. Investigators from the Bureau of Alcohol Tobacco and Firearms determined that bombs planted at the Democratic and Republican Party headquarters were genuine devices.

Joe Raedle/Getty Images

The American flag is lowered to half-staff atop the U.S. Capitol Building following the death of...

Bomb technicians blasted the devices with water cannons to essentially break them apart and render them harmless. Investigators are examining the recovered pieces to look for clues about how the devices was constructed and the sources of the components, sources said. They have also released a surveillance photo of a heavily cloaked man they believe planted the explosives.

"The devices were disabled and turned over to the FBI for further investigation and analysis," Capitol Police said Thursday.

Another task will be to determine why footage shows some intruders roaming congressional corridors dressed in paramilitary gear, carrying zip ties and duffle bags that appear to have a purpose beyond posing for selfies or waving flags.

Two officials familiar with the investigation said law enforcement is working to not only identify the hundreds of rioters, but distinguish between those who followed the mob, and those who may have wished to harm Vice President Mike Pence or congressional leaders who were gathered to complete the certification of the 2020 presidential election.

Law enforcement officials told ABC News that investigators will use cellphone data to identify individual users whose phones sent out signals from inside the Capitol.

ABC News national security analyst and former Deputy Assistant Secretary of Defense Mick Mulroy, a retired CIA officer and U.S. Marine, said he expects the FBI will be conducting a full counterintelligence sweep on all those who participated in the assault, especially those who were apprehended, to determine possible foreign intelligence ties.

Andrew Harnik/AP

Sen. Tim Scott stops to look at damage, Jan. 7, 2021, after protesters stormed the Capitol in Wa...

"It is possible, if not likely, that foreign intelligence service, including the Russians, would clandestinely fund groups like the Proud Boys or Oath Keepers as part of a covert influence campaign to pit Americans against one another," Mulroy said. "It is also possible that they would exploit an opportunity to go into the facilities and offices in the Senate or House that contain sensitive information."

Department of Justice officials told reporters that their goal is to identify people and, in certain cases, arrest them with "placeholder charges" as they investigate how they came to the Capitol and how much planning was involved in the attack. Kohl said it would be too early at this point to discuss any evidence of a foreign operation.

In addition to all of the efforts underway to sort out charges for those involved in the Capitol Breach, congressional leaders said they anticipate a separate investigation will be conducted to examine the conduct of U.S. Capitol Police officers in the heat of the unrest.

With so many investigative threads being pulled, federal and local authorities have repeatedly emphasized that more arrests and charges are expected in the coming days, weeks, and months.

"Today's charges are just the beginning of the FBI's ongoing efforts to hold those responsible for the criminal acts of violence and destruction that unfolded during the U.S. Capitol building breach on January 6th," FBI Director Christopher Wray said Friday.

Meanwhile, as President Trump reportedly discusses the possibility of pardoning himself before leaving office, investigators signaled Friday that they werenot likely to pursue chargesagainst those accused of inciting the riots at a rally on the National Mall earlier Wednesday. Speakers at the rally included the president and several members of his family.

"We don't expect any charges of that nature," a Justice Department official said Friday.

On Friday night, FBI Assistant Director in Charge Steven M. D’Antuono said during a press call that the charges made against the Capitol intruders "are just the start of the results of the extensive work done by the FBI and our partners over the last few days, and we are far from done."

"The rioting and destruction we saw will not be tolerated by the FBI, and I can assure you that the FBI Washington Field Office and additional Headquarters and field office resources are working diligently around the clock to investigate those responsible for the violence and criminal actions we saw unfold on Wednesday," he added.

D’Antuono also warned those involved who have not been identified or arrested: "Just because you’ve left the D.C. region, you can still expect a knock on the door if we find out that you were part of criminal activity inside the Capitol. Bottom line—the FBI is not sparing any resources in this investigation."