After nearly three years, federal officials are still looking for a suspect as part of the investigation into a pair of pipe bombs that were planted outside the Republican National Committee’s (RNC) and Democratic National Committee’s (DNC) offices in Washington, D.C., in January 2021.

A bulletin issued by the FBI on Thursday said a $500,000 reward, which would be given in exchange for information leading to an individual’s arrest and conviction, “remains in effect.” The bureau also said “identifying the perpetrator of this attempted attack remains a priority” for law enforcement and offered information on how to contact investigators, including through anonymous tips.

Federal authorities say a pair of pipe bombs were planted outside the RNC’s and the DNC’s offices in Washington, D.C., on the evening of January 5, 2021, the night before the U.S. Capitol riot on January 6. Surveillance video of the suspect previously released to the public shows a hooded figure carrying around a backpack and, at one point, sitting on a bench looking at what appears to be a phone.

The FBI said the bombs did not denote, but the agency stressed that “it is important to remember the suspect walked along residential and commercial areas in Capitol Hill just blocks from the U.S. Capitol with viable pipe bombs that could have seriously injured or killed innocent bystanders. Moreover, the suspect may still pose a danger to the public or themselves.”

Authorities located the bombs on January 6, which is the day when rioters breached the U.S. Capitol and disrupted lawmakers as they worked to certify Joe Biden’s presidential victory, after a local resident said she spotted the device near the RNC and reported it to a security guard.  The pipe bomb found near the DNC reportedly prompted the evacuation of then-Vice President-elect Kamala Harris from the building.

“Over the past three years, a dedicated team of FBI agents, analysts, data scientists, and law enforcement partners has worked thousands of hours conducting interviews, reviewing physical and digital evidence, and assessing tips from the public about who may have placed pipe bombs on Capitol Hill,” said David Sundberg, assistant director in charge of the FBI Washington Field Office.

“The tips we have received so far from the American people have helped us advance the investigation, and we ask the public to continue to assist us by taking a fresh look at our Seeking Information webpage, which includes images and video of the suspect, the suspect’s backpack, the suspect’s shoes, the explosive devices, and a map of the route the suspect walked the night the pipe bombs were placed,” Sundberg added.

Republicans in Congress have pressed federal law enforcement to be more forthcoming in what they have found in their investigation. Steve D’Antuono, the former assistant director in charge of the FBI’s Washington Field Office, told the House Judiciary Committee last year that FBI investigators found phone carrier data had been corrupted, frustrating their January 6 pipe bomb investigation.

While facing a line of questioning during a House hearing in July, FBI Director Christoper Wray refused to divulge findings from the bureau’s years-long probe. But he did say, “I will tell you we have done thousands of interviews, reviewed something like 40,000 video files of which this is one, assessed 500-something tips, reviewed the devices.”