The FBI has targeted a single attacker in an investigation into the death of a Capitol officer

The FBI says it is targeting a single attacker as it continues to investigate the death of U.S. Capitol police officer Brian Sinick, who died from injuries sustained in the Jan. 6 uprising.

A federal law enforcement source and another close to the investigation confirmed the news on Saturday.

Cynic, 42, was injured “during a physical engagement with protesters” and returned to his office, where he collapsed, according to a Capitol police statement. He was taken to hospital, where he later died on January 7.

Agents have not determined the exact cause of Sicknick̵

7;s injuries, but recently said they suspected he was from a potential spray irritant, such as a bear spray he inhaled during the riot. The investigation into Sicknick’s death is being treated as an assault.

According to officials, the video shows a man attacking several police officers, including Siknik, with a spray. The suspect was also heard discussing the alleged attack before the incident, officials said.

Federal authorities have not identified the suspects and the FBI has not yet released the video to the public.

Five people, including Siknik, have died after a crowd of supporters of then-President Donald Trump stormed the Capitol to prevent Congress from formally accepting the Electoral College votes that delivered President Joe Biden in the November election.

This is an evolving story; check for updates.