THE slain Capitol cop laid in honor at the Rotunda and was praised as a hero who put the safety of others first.
President Joe Biden attended the ceremony for William "Billy" Evans, 41, who was killed after a knife-wielding man rammed the barricades of the Capitol lawn with his vehicle.
The driver, Noah Green, 25, was shot dead by cops and investigators believe he had been delusional and having suicidal thoughts.
Evans, who had two young children, was an 18-year veteran of the force.
The president said: "He was the one who always kept his word. He was the one who, just like the folks I grew up with, wasn't capable of saying no when you needed him."
"Your dad is a hero," Biden told the children. ."It's in your blood," before adding "the moment of the smile comes without the tear."
Ahead of today's service, a statement from US Capitol Police said: "As we mourn the loss of Officer Billy Evans, we are grateful for the honor bestowed upon him by Congress."
US Capitol cops gathered outside the building and lined the streets as the hearse carrying the body of Evans entered the Capitol grounds around 10.30am.
Family and friends stood at the top of the steps of the Capitol building as his coffin, draped in the American flag, was removed from the hearse.
During the ceremony, the Chaplain of the United States Senate said they are experiencing "anger, confusion and fear" over the loss of "a son, a father, a friend, and a partner."
Paying tribute to Evans' children, House Speaker Nancy Pelosi said: "Logan and Abigail, no words are adequate. We can only imagine your sadness.
"So many know about your dad and know he is a hero - his name will always be on our lips and in our hearts."
Rep. Tim Ryan, who heads a committee which oversees the Capitol Police, said: "The loss of Officer Evans is yet another stark reminder of what our brothers and sisters in uniform risk every day to protect us.
"The honor of lying in state under the Capitol dome is befitting of this American hero."
Paying tribute to Evans, House Minority Leader Kevin McCarthy tweeted: "With heavy hearts and in recognition of his courage and sacrifice, a grateful nation bids farewell to Officer Billy Evans, a true hero.
"His loss is enormous - our prayers are with his two children, his families, and his colleagues in Capitol Police."
Last night, Senate Majority Leader Chuck Schumer said: "On April 2, a senseless attack on the Capitol claimed the life of Officer William 'Billy' Evans.
"Officer Evans will lie in honor under the Capitol rotunda, at the very center of the democracy he gave his life to protect."
On Tuesday he added: "Officers are approached by hundreds of lost tourists a day, lucky ones bump into Billy" before dubbing him a "fellow of infinite jest."
"Billy was a man of many crews - one you'd want to be stationed with," Schumer added, before saying Evans received "joy and laughter out of life's smallest moments."
"Those of you who remember Billy need to speak his name," he finalized.
Senator Elizabeth Warren said Evans "made the ultimate sacrifice to protect our Capitol".
"We are forever in his debt," she said.
In a statement earlier this month, his family said his two children - Logan and Abigail - were the most important thing in his life.
He was remembered by colleagues and friends as a man with a sense of humor who loved baseball and golf.
"His most cherished moments were those spent with them building with Lego, having lightsaber duels, playing board games, doing arts and crafts, and recently finishing the Harry Potter series," the family said.
"He was always so eager to show how proud he was of everything they did."
The family said Evans was proud of his job - and his friendship with colleagues near the "North Barricade" of the Capitol complex was one of the best parts of it.
"We hold them in our hearts, as we know they acutely share our grief," they said.
On the Senate floor on Monday evening, Senator Dick Durbin, said Evans was a "familiar and friendly face" at the barricade where he was killed.
"Every day it is incumbent on those of us who work in this building to remember this officer, and to thank him, and the men and women of the U.S. Capitol Police who have given so much to keep us safe," Durbin said.
Evans death came just three months after a violent mob of Trump supporters stormed the Capitol, injuring dozens of Capitol Police officers.
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Officer Brian Sicknick died during the carange and two men have been arrested and charged with assaulting him with bear spray.
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Sicknick and Evans are two of only six Capitol Police officers who have been killed in the line of duty in the forces nearly 200-year history, according to the department.
Another cop, Howard Liebengood, took his own life in the days after January 6, Associated Press reports.