The attack lasted about three minutes from the first shot at the Document Door to Weston's arrest in DeLay's outer office. Officer Douglas McMillan, normally posted outside, was nearby retrieving keys to get a wheelchair for a visitor when Weston opened fire. McMillan returned fire immediately, hitting Weston, but the gunman was already running into the building. Weston had wounded a tourist named Angela Dickerson with a stray round during the exchange. McMillan could not pursue with his weapon drawn through the crowd. Weston turned down a short corridor and pushed through the first door he found, which led to a small suite of offices used by senior Republican representatives - then-Majority Whip Tom DeLay and Representative Dennis Hastert, who would become Speaker of the House the following January. Detective Gibson was inside. Hearing the shots, Gibson ordered the staff under their desks and stepped toward the door with his weapon out. Weston shot him once in the chest. Mortally wounded, Gibson returned fire and hit Weston four times. Other officers arrived seconds later and arrested Weston where he had fallen.

Senator Bill Frist of Tennessee, who would later become Senate Majority Leader, was a board-certified heart and lung transplant surgeon before he had been a senator. He had been presiding over the Senate floor a few minutes before the shooting and was still in the Capitol. Hearing what had happened, Frist rushed to the scene. He performed emergency resuscitation on Weston, the man who had just killed two of his protectors, and rode with him in the ambulance to D.C. General Hospital. The choice was not popular with everyone, but it was the choice of a doctor confronted with a dying patient. Gibson was rushed to MedStar Washington Hospital Center, where he died in surgery. Chestnut was taken to George Washington University Hospital and pronounced dead there. Two of the four people who started the day in the Document Door corridor were gone by sunset. Weston survived. He has not stood trial in the 28 years since.

Two days after the shooting, on July 26, the bodies of Jacob Chestnut and John Gibson were carried into the Rotunda of the Capitol and placed on the Lincoln catafalque - the same wooden bier that had supported the bodies of Presidents Lincoln, Garfield, McKinley, Harding, Taft, Kennedy, Hoover, Eisenhower, Johnson, Reagan, and Ford. They were the first police officers to receive the tribute of lying in honor in the Rotunda. Chestnut was the first African American. Members of Congress and ordinary Washingtonians lined up for hours to pass the caskets. President Bill Clinton spoke at Chestnut's funeral. Military jets flew the missing-man formation overhead. Gibson was buried at Arlington National Cemetery. He had been married to the niece of Representative Joe Moakley of Massachusetts and left three children, aged 17, 15, and 14. The Boston Red Sox held a moment of silence before their game with the Kansas City Royals on August 11. A post office in Maryland was renamed for both officers. So was a building at Shaw Air Force Base in South Carolina where Chestnut had served. The Document Door itself was renamed the Chestnut-Gibson Memorial Door.

Russell Eugene Weston Jr. grew up in Valmeyer, Illinois, a town of 900 people in the Mississippi flood plain. He graduated from Valmeyer High School in 1974 and moved to a tiny mining town called Rimini in the Montana mountains, where neighbors found him eccentric and isolated. He believed his neighbor was using a television satellite dish to spy on him. He believed Navy SEALs were hiding in his cornfield. He was diagnosed with paranoid schizophrenia in 1992 and stopped taking his medication. Eighteen months before the shooting he moved back to Valmeyer and obsessively cut down trees in his family's yard. Two days before the shooting, at his grandmother's request, he shot fourteen cats with a shotgun. He told the court-appointed psychiatrist after the attack that he had stormed the Capitol to prevent the United States from being annihilated by disease and legions of cannibals. He was found incompetent to stand trial in 1999. A federal judge ordered him forcibly medicated in 2001, and the U.S. Court of Appeals for the District of Columbia Circuit upheld the order. In 2004 the court ruled that even with treatment Weston was not competent to be tried, and suspended but did not dismiss the murder charges against him. He remains under civil commitment at the Federal Medical Center in Butner, North Carolina. The shooting was one of the events that motivated Congress to build the Capitol Visitor Center, which finally opened in 2008 - a security buffer that did not exist when Jacob Chestnut and John Gibson stood at the Document Door.