In this undated photo released by the FBI, Amor Ftouhi is shown. Ftouhi, a Canadian man, shouted in Arabic before stabbing a police officer in the neck at the Bishop International Airport in Flint, Mich., on Wednesday, June, 21, 2017. The FBI says Ftouhi, 49, tried unsuccessfully to buy a gun while in the United States for five days. (FBI via AP)
David P. Gelios, Special Agent in Charge, Detroit Division of the FBI, speak during a news conference in Detroit, Thursday, June 22, 2017. Amor Ftouhi, a Canadian man, shouted in Arabic before stabbing a police officer in the neck at the Bishop International Airport in Flint, Mich., on Wednesday. The FBI says Ftouhi, 49, tried unsuccessfully to buy a gun while in the United States for five days. (AP Photo/Paul Sancya)
David P. Gelios, left, Special Agent in Charge, Detroit Division of the FBI, and Daniel L. Lemisch, Acting U.S. Attorney of the Eastern District of Michigan, speak during a news conference in Detroit, Thursday, June 22, 2017. Amor Ftouhi, a Canadian man, shouted in Arabic before stabbing a police officer in the neck at the Bishop International Airport in Flint, Mich., on Wednesday. The FBI says Ftouhi, 49, tried unsuccessfully to buy a gun while in the United States for five days. (AP Photo/Paul Sancya)
FILE - This undated file photo provided by the FBI shows Ahmad Khan Rahami. A federal judge refused Thursday, June 22, 2017, to throw out criminal charges that could result in a mandatory life prison sentence for Rahami. Rahimi, 29, pleaded not guilty to detonating a pipe bomb near a charity run in Seaside Park, New Jersey, and planting two pressure cooker bombs in Manhattan in September. (FBI via AP, File)
This poster released by the FBI asks for information on James T. Hodgkinson of Belleville, Ill. Police believe that Hodgkinson opened fire on Republican lawmakers at a congressional baseball practice Wednesday, June 14, 2017 in Alexandria, Va., wounding House GOP Whip Steve Scalise of Louisiana and several others as congressmen and aides dove for cover. (FBI via AP)
Eric C. Conn, seen here in a photo issued by the FBI, is accused of attempting to bilk the federal government with more than $500 million worth of bogus Social Security disability applications.
FILE - In an Aug. 21, 2013 file photo, outgoing FBI director Robert Mueller speaks during an interview at FBI headquarters, in Washington. Former FBI Director Mueller addressed graduates at at Tabor Academy, a private college preparatory school in Marion, Mass., on Monday, May 29, 2017, less than two weeks after his appointment as special counsel to oversee an investigation into possible connections between Russia and President Trump’s 2016 election campaign. (AP Photo/Evan Vucci, File)
FILE - This undated combination of file photos provided by the FBI, left, and the California Department of Motor Vehicles shows Tashfeen Malik, left, and Syed Farook. Authorities have released a detailed report that includes the accounts of more than two dozen law enforcement officers involved in a shootout with a husband and wife who killed 14 people and wounded 22 others in the San Bernardino terror attack. San Bernardino County prosecutors released the report Thursday, May 25, 2017. It details how officers identified husband-and-wife assailants Syed Rizwan Farook and Tashfeen Malik and a gunfight that ensued after officers tried to stop the fleeing couple. (FBI, left, and California Department of Motor Vehicles via AP, File)
In this March 20, 2017, file photo, House Intelligence Committee member Rep. Trey Gowdy, R-S.C., questions then-FBI Director James Comey and National Security Agency Director Michael Rogers as they testify on Capitol Hill in Washington. President Donald Trump is considering nearly a dozen candidates to succeed ousted FBI Director James Comey, choosing from a group that includes several lawmakers, attorneys and law enforcement officials.(AP Photo/J. Scott Applewhite, File)
Acting FBI Director Andrew McCabe listens on Capitol Hill in Washington on May 11, 2017, while testifying before a Senate Intelligence Committee hearing on major threats facing the U.S. (Associated Press) **FILE**
FILE - In this March 20, 2017, file photo, House Intelligence Committee member Rep. Trey Gowdy, R-S.C., questions then-FBI Director James Comey and National Security Agency Director Michael Rogers as they testify on Capitol Hill in Washington. President Donald Trump is considering nearly a dozen candidates to succeed ousted FBI Director James Comey, choosing from a group that includes several lawmakers, attorneys and law enforcement officials.(AP Photo/J. Scott Applewhite, File)
Acting FBI Director Andrew McCabe sits with a folder marked "Secret" in front of him while testifying on Capitol Hill in Washington, Thursday, May 11, 2017, before the Senate Intelligence Committee hearing on major threats facing the U.S. (AP Photo/Jacquelyn Martin)
A person walks past as the FBI serves a search warrant at the office of Strategic Campaign Group on Thursday, May 11, 2017 in Annapolis, Md. Kelley Rogers, the president of the firm, told reporters the investigation relates to work the firm did for former Virginia Attorney General Ken Cuccinelli, a Republican who lost Virginia’s 2013 governor’s race. The windows in the firm's doors leading into its third floor suite in the building on Main Street in Maryland's capital were obscured as FBI agents served the search warrant. (Joshua McKerrow/The Baltimore Sun via AP)
From left, acting FBI Director Andrew McCabe, CIA Director Mike Pompeo, Director of National Intelligence Dan Coats, National Security Agency Director Adm. Michael Rogers, Defense Intelligence Agency Director Lt. Gen. Vincent Stewart, and National Geospatial-Intelligence Agency (NGA) Director Robert Cardillo, prepare to testify on Capitol Hill in Washington, Thursday, May 11, 2017, before the Senate Intelligence Committee hearing on major threats facing the U.S. (AP Photo/Jacquelyn Martin)
Acting FBI Director Andrew McCabe sits with a folder marked "Secret" in front of him while testifying on Capitol Hill in Washington, Thursday, May 11, 2017, before the Senate Intelligence Committee hearing on major threats facing the U.S. (AP Photo/Jacquelyn Martin)
FILE - In this July 20, 2016, file photo, FBI Deputy Director Andrew McCabe listens during a news conference at the Justice Department in Washington. McCabe was elevated to acting FBI director after FBI director James Comey was fired by President Donald Trump on May 9, 2017. (AP Photo/Jacquelyn Martin, File)
In this Oct. 28, 2013, file photo, President Barack Obama and FBI Director James Comey participate in the installation ceremony for Comey as FBI director, at FBI Headquarters in Washington. President Donald Trump abruptly fired Comey on May 9, 2017, dramatically ousting the nation's top law enforcement official in the midst of an FBI investigation into whether Trump's campaign had ties to Russia's election meddling. (AP Photo/Charles Dharapak, File)