By Patricia Zengerle

WASHINGTON (Reuters) -A year after then-President Donald Trump's supporters launched a deadly assault on the U.S. Capitol, signs of heightened security are visible everywhere, from police riot shields ready near doorways to metal detectors outside the House of Representatives chamber.

Miles of steel fencing that ringed the Capitol complex after the riot came down in July. The thousands of armed National Guard troops deployed immediately after the Jan. 6, 2021, attack have long gone home.

But U.S. Capitol Police officers - in larger numbers and more heavily equipped than in the past - are posted around the grounds, while the department has added defensive equipment. Lighter fencing remains in place in some locations.

Once thronged by 2.5 million visitors a year, Capitol hallways now echo with emptiness. Almost everyone who comes into the complex must be a member of Congress or display a staff ID - a restriction prompted by the COVID-19 pandemic.

Congress passed a $2.1 billion bill in July that provided $100 million for the Capitol Police force, $300 million for new security measures and more than $1 billion for the Pentagon - of which $500 million will go to the National Guard, whose funds were depleted in the security ramp-up after the riot.

Capitol Police Chief Thomas Manger, hired to revamp the force after the attack, on Wednesday acknowledged that lawmakers are seeing more security equipment around the Capitol.

"I'm sure that as you walk around the campus there's times when you pass through a door and you'll notice that there's a stack of shields behind the door. So we've got them deployed around the campus in case we need them," Manger said, adding that the force plans to hire about 280 more officers this year.

Manger has said the Capitol Police as an organization is stronger and better prepared now than before the riot and has worked to fix leadership, intelligence and planning failures.

Around 140 police officers were injured when Trump's supporters stormed the building, trying to prevent Congress from formally certifying his 2020 election loss to President Joe Biden. The rioters fought with police for hours, smashed windows and sent lawmakers and staff running for their lives.

One officer who battled rioters died the day after the attack and four who guarded the Capitol later died by suicide. Four rioters also died, including a woman https://www.reuters.com/article/us-usa-election-death/woman-killed-in-siege-of-u-s-capitol-was-veteran-who-embraced-conspiracy-theories-idUSKBN29C2NV who was shot by a police officer while trying to climb through a shattered window in a door inside the Capitol leading into an area known as the Speaker's Lobby.

Lawmakers from both parties joined in calls for better security after the assault, but the reaction to various steps taken has been partisan. In particular, some House Republicans have voiced complaints about the five metal detectors installed at the entrances to the House chamber, where police on the day of the riot barricaded doors and lawmakers dove for cover as people in the mob tried to force their way in.

Some House Republicans, staunch defenders of gun rights, have called the metal detectors a political show, with congressmen Andrew Clyde and Louie Gohmert filing a lawsuit seeking their removal.

Security is due to be heavier than usual on Thursday, the anniversary of the attack. The House and Senate both are planning events to mark the anniversary and Biden plans to give a speech at the Capitol. The Senate is scheduled to be in session on Thursday. The House is not.

Senate Majority Leader Chuck Schumer, a Democrat, on Wednesday said the false claims about a stolen election that underpinned last year's attack could bring fresh violence again at some point.

"The insurrection will not be an aberration. It well could become the norm," Schumer said, unless Congress addresses "the root causes" of Jan. 6 through election reforms.

(Reporting by Patricia Zengerle, additional reporting by Richard Cowan; Editing by Will Dunham and Scott Malone)