Updated

Two men have been charged with assaulting fallen U.S. Capitol Police Officer Brian Sicknick on Jan. 6 after prosecutors say video evidence shows them dousing Sicknick and other law enforcement officers with a chemical spray outside the building.

But the suspects have not been charged with homicide, and prosecutors so far have not implicated anyone directly in causing Sicknick's demise, as an official cause of death remains pending.

AUTOPSY RESULTS PENDING IN OFFICER BRIAN SICKNICK DEATH INVESTIGATION

"The attack on the U.S. Capitol and on our police officers, including Brian Sicknick, was an attack on our democracy," said U.S. Capitol Police Acting Chief Yogananda Pittman. "Those who perpetrated these heinous crimes must be held accountable, and -- let me be clear -- these unlawful actions are not and will not be tolerated by this Department."

Julian Elie Khater, 32, of Pennsylvania, and George Pierre Tanios, 39 of Morgantown, West Virginia, were arrested Sunday and were expected to make a court appearance Monday, the Washington Post first reported.

Each faces nine counts, including assault with a deadly weapon against Sicknick, a second Capitol police officer identified in court documents as "C. Edwards," and a D.C. Metropolitan Police officer identified as "B. Chapman."

Tanios was ordered held pending a Thursday detention hearing. Wearing an orange jumpsuit and mask, he appeared before Magistrate Judge Michael Aloi, who was in his chambers in West Virginia, via a video feed where the charges against him were read. 

He faces several felonies, including assault with a dangerous weapon, conspiracy to injure a law enforcement officer and obstruction of a federal proceeding. He faces up to 60 years in prison. 

Tipsters helped identify the two suspects using surveillance and body-camera images released by the FBI. According to charging documents, video shows Khater asking Tanios for a can of bear mace at 2:14 p.m. near the Lower West Terrace of the Capitol. About nine minutes later, Khater, who says he was struck with bear spray, is seen discharging a canister into the faces of Sicknick and the other officers.

The criminal complaint filed in the U.S. District Court for the District of Columbia also revealed that Khater and Tanios grew up together in New Jersey, and that Khater had worked in State College, Pennsylvania, and Tanios owns a business in Morgantown, West Virginia.

CAPITOL RIOTER CHARGED WITH ASSAULTING DC OFFICER BURRIED STOLEN POLICE BADGE IN NY BACKYARD: PROSECUTORS

The investigation into Sicknick’s death remains ongoing, as the Office of the Chief Medical Examiner has not released an official cause of death, and how exactly the officer died remains publicly unknown. Sicknick died at the hospital at approximately 9:30 p.m. the evening of Jan. 7. Lawmakers last month honored Sicknick, as his remains laid in honor in the Capitol Rotunda before a ceremonial send-off on the steps to Arlington National Cemetery, where he was interred.

CLICK HERE TO GET THE FOX NEWS APP

Media reports have been conflicting — unnamed law enforcement sources initially told outlets Sicknick was struck in the head by a fire extinguisher, while others speaking on condition of anonymity countered argued there was no immediate evidence showing that Sicknick suffered any blunt force trauma. Some have also suggested exposure to a chemical irritant could have played a role, and Sicknick's eldest  brother, Ken Sicknick, said in an interview with Pro Publica that the officer suffered some sort of blot clot or stroke.

U.S. Capitol Police has said that Sicknick "passed away due to injuries sustained while on-duty."  According to the department, he "was responding to the riots" on Jan. 6 at the U.S. Capitol and "was injured while physically engaging with protesters." He then "returned to his division office and collapsed" and was taken to a local hospital "where he succumbed to his injuries." 

Fox News' Jake Gibson contributed to this report.