The two pipe bombs that were discovered on Jan. 6 near the U.S. Capitol shortly before a mob stormed the building are believed to have been planted the night before, according to a law enforcement official familiar with the investigation and video footage obtained by The Washington Post.

The explosive devices, which were placed blocks from one another at the headquarters of the Republican and Democratic national committees, have been largely overshadowed by the violent attempted insurrection at the Capitol. But finding the person suspected of planting both bombs remains a priority for federal authorities, who last week boosted the reward for tips leading to the person’s arrest from $50,000 to $75,000.

The FBI said its agents are “using every tool in our toolbox” and have interviewed more than 1,000 residents and business owners in the neighborhood where the devices were found. On Friday morning, the FBI released additional information that confirmed The Post’s reporting about the timing of the placement of the bombs and raised the reward offered to $100,000.

The Post spoke to residents, property managers and business owners to obtain exclusive video of the suspect in the moments before the individual allegedly placed the bomb in an alley behind the Republican National Committee, one block from the Capitol grounds.

On Jan. 5 at 8:13 p.m., a security camera captured the suspect carrying a backpack, according to a resident who reviewed the footage and provided a copy to the FBI. The suspect was walking eastbound on C Street SE, headed toward an entrance to an alley that curved toward the Republican National Committee building. The Post did not obtain that footage but confirmed the homeowner’s account with a law enforcement official familiar with the investigation.

Seconds later, in video obtained by The Post, the suspect can be seen in the alley, known as Rumsey Court. The individual is wearing a light-colored sweatshirt and carrying the backpack near their waist, matching photographs that have been released by the FBI, and walking west past a row of homes. The suspect is believed to be walking toward the area behind the Republican National Committee building and the Capitol Hill Club to place the explosive device, according to the official familiar with the investigation, who spoke on the condition of anonymity to discuss sensitive matters.

At 8:13 p.m., a security camera captures the suspect in Rumsey Court wearing a light-colored sweatshirt. (Obtained by The Washington Post)

Another video shows the suspect carrying a backpack near their waist as they approach the area where the bomb was discovered on Jan. 6. They appear to be wearing a mask and gloves. According to the law enforcement official, this is the last known sighting of the suspect before the placement of the bomb.

This video, taken at 8:15 p.m., is the last known sighting of the suspect before they allegedly placed the bomb. (Obtained by The Washington Post)

When federal officials asked the public for information about the suspect, they circulated still images drawn from this video. For unknown reasons, the suspect did not immediately leave the area. Another video obtained by The Post shows the suspect retracing their steps on Rumsey Court at 8:16 p.m., again walking westbound toward the RNC building. The individual is moving at a brisk pace and still carrying a backpack near their waist.

The suspect does not immediately leave the area, instead walking westbound toward the RNC building. (Obtained by The Washington Post)

One minute later, the suspect is seen walking eastbound on Rumsey Court — away from the area where the pipe bomb was discovered. They are wearing the backpack on their back.

At 8:17 p.m., the suspect is seen walking away from the area where the pipe bomb was discovered near the RNC. (Obtained by The Washington Post)

The same person is suspected of placing the bomb at the Democratic National Committee building, according to the FBI. It is not clear which bomb was placed first. On Friday, the FBI released an image of one of the devices. The bureau described the suspect as wearing Nike Air Max Speed Turf shoes in yellow, black and gray and said that the person is believed to have placed both bombs between 7:30 and 8:30 p.m. on Jan. 5.

Barry Black, a retired FBI special agent bomb technician, said photos of the devices suggested that they were simple and that the visible components were common and easily found. Black said the devices appeared to incorporate mechanical timers as switches and said he saw no indication in the photos of any other triggering mechanism.

Black said the individual could have been seeking to kill or injure, or could have simply wanted to “send a message” by targeting the nation’s two largest political parties. Steven Sund, who resigned as chief of the Capitol Police in the wake of the riot, has said he suspects the bombs were an intentional effort to draw officers away from the grounds of the Capitol.

The bomb behind the RNC was discovered on Jan. 6 at around 12:45 p.m., about 90 minutes before rioters entered the Capitol. Resident Karlin Younger was on her way to do laundry when she spotted something unusual on the ground between a recycling bin and a rat trap. Younger said in an interview that she bent down to inspect the device, which was attached to what appeared to her to be a kitchen timer. The timer was set to 20 minutes, she said. She did not hear any ticking and could not tell if the timer was active. She alerted a nearby security guard, who she said inspected the device and then notified law enforcement.

The device was considered “live,” meaning it contained viable explosive material, according to Steven Blando, a spokesman for the Washington Field Division of the Bureau of Alcohol, Tobacco and Firearms. It was disarmed at the site, Blando told The Post.

Around 1:15 p.m., officials have said, the second bomb was discovered several blocks away next to a bench outside the DNC. It, too, was live and was disarmed on site, Blando said.

Peter Hermann, Elyse Samuels and Matt Viser contributed to this report.