Yes. As you specify only incidents where someone died, I'll pass over the time in 1954 when a group from the Puerto Rican Nationalist Party starting shooting on the House floor, wounding five representatives, or the time in 1915 where someone tried to bomb the Senate Chamber but couldn't reach it (they blew up the Reception Room instead), and various other incidents -- and skip over to....

July 24, 1998, a Friday.

Russell E. Weston Jr. walked in the Document Room door on the House side of the Capitol. This was a normal thing to do; it was open to the public, and various aides and tourists were there, as well as Officer Jacob J. Chestnut Jr. and Officer Douglas P. McMillan, two of over 1000 officers of the Capitol Police.

What was not normal was he was carrying a .38-caliber revolver. The metal detector went off; before anyone had a chance to react, the gunman shot Officer Jacob J. Chestnut Jr. in the back of his head. Tourists and aides fled. Officer Douglas P. McMillan was able to get his gun out and open fire back, but he missed, accidentally wounding one of the tourists.

The gunman started running towards the suite of the majority whip (the Republican Tom DeLay) and an unnamed female bystander. Detective Gibson was inside the room and shouted for the aides to take cover. As he tried to draw his firearm the bystander came to the door; he moved her to safety, and while doing so the gunman shot him in the chest. Gibson then managed to get out his own gun and shoot the assailant's legs. This was sufficient for the gunman to be subdued.

The entire incident lasted 17 seconds. Both Officer Chestnut and Detective Gibson died. They were later Lain in Honor in the Capitol Rotunda; the only other two people to have had that honor are Rosa Parks and Reverend Billy Graham. (The Capitol Rotunda has also had many Lain in State, including Abraham Lincoln, John Joseph Pershing, and John McCain. Those who are Lain in State are guarded by one member each of the branches of the Armed Forces, while those who are Lain in Honor are guarded by Capitol Officers.)

...

At the time of the shooting, Russell E. Weston Jr. had suffered paranoid schizophrenia for 20 years. In 1996 he visited the offices of the CIA and explained he was an operative named "The Moon", and he had created a Ruby Surveillance System for NASA out of a ruby, a watch, and a wheel; this device could reverse time. He also explained that President Clinton "is a Russian clone, brought to the United States for the purposes of communist insurgency".

He was amongst the list of many the Secret Service had of people who had threatened the President of the United States. (Specifically, he told a sheriff's deputy that if President Clinton ever tried to kill him, he would kill him first. He denied saying this in a later Secret Service interview.)

In May 1996, Weston came to an emergency room and told them federal agents were poisoning him with soap. The authorities later decided he could not be committed to a mental hospital.

When asked why he attacked the Capitol, he explained if did not, he would be come infected with "Black Heva", which he called "most deadliest disease known to mankind" and was spread by the corpses of cannibal victims. He explained the Ruby Survelliance System (the one that allows for time travel) was being kept in a Senate safe and he was trying to get to it.

There was a legal struggle if he could stand trial. The government tried to get permission to forcibly give medication; in 2001 the United States Court of Appeals upheld the decision that this was allowable. Even with the medication, it was decided in 2004 he was not able to stand trial; in a 2008 motion, the psychologist Holly Rogers said "sometimes there are individuals who simply do not respond to medication."

Had our civil commitment system contained an effective follow-up mechanism for monitoring Russell Weston after his release from involuntary hospitalization and had he been on a regimen of long-acting medications, it seems possible that he may not have deteriorated to such an extent subsequent to his release from the hospital. Unfortunately, Weston was instead released without effective follow-up and his illness grew increasingly more severe.

-- Veronica Manahan, in an article for the APA

...

As far as security goes, the biggest change as a result of the shooting was an underground visitor's center. The idea of an underground expansion to the Capitol had been around since 1971 (as recommended by the American Institute of Architects, you can see a picture here); the shooting was the spark needed to get the project off the ground.

It was opened on December 2, 2008. You can read more about the Capitol Visitor's Center at the government's official website.

The United States Capitol is a monument, a working office building, and one of the most recognizable symbols of representative democracy in the world. Visitors are welcome to enter the building through the Capitol Visitor Center, located underground on the east side of the Capitol. The U.S. Capitol Visitor Center provides an increased focus on visitor comfort, safety and security resulting in a seamless, positive visitor experience at the U.S. Capitol.

...

Feinberg, A. (2002). Forcible Medication of Mentally Ill Criminal Defendants: The Case of Russell Eugene Weston, Jr. Stanford Law Review, 54(4), 769-791. doi:10.2307/1229578

Fern, M. (23 November 1998). For Capitol Police, Nothing is the Same. Washington Post.

Manahan, V. J. (2004). When our system of involuntary civil commitment fails individuals with mental illness: Russell Weston and the case for effective monitoring and medication delivery mechanisms. Law & Psychology Review, 28, 1–33.

Margolis, E. H. (2000). The failure of civil confinement: How Russell E. Weston Jr. slipped through the cracks and the potential for many more to follow. New Eng. J. on Crim. & Civ. Confinement, 26, 129.

Miller, B. (23 April 1999). Capitol Shooter's Mind-Set Detailed. Washington Post.

Petersen, R. E., Manning, J. E., & Hemlin, E. (2011). Violence Against Members of Congress and Their Staff: Selected Examples and Congressional Responses. Congressional Research Service.

Toward a Master Plan for the United States Capitol: Phase II, the Alternatives. (1977). United States: U.S. Capitol Planning Group.