Garrett M. Graff is editor of Washingtonian magazine and the author of “The Threat Matrix: The FBI at War in the Age of Global Terror.”

The FBI lists its official address as 935 Pennsylvania Ave. NW, as if one could wander by the angular, concrete, block-size headquarters without noticing the J. Edgar Hoover Building. The aging 11-story monstrosity — an especially ugly example of the Brutalist movement in architecture — is nearing the end of its life, and not even preservation experts want to save it.

But that doesn’t mean the bureau should leave the District.

The FBI’s requirements have shifted with time: Digital records have negated the need for floor upon floor of fingerprint files, while staff increases have led to workers being scattered across more than 20 annexes in this area alone. The thousands of Hoover Building staffers who spend their days in its drab corridors would almost certainly love a building filled with natural light and less linoleum.

Planners have estimated that selling or trading the land, one of the largest parcels between Capitol Hill and the White House, could net close to $900 million — enough for the cash-strapped government to build a huge, modern complex in the suburbs. Security concerns after 9/11 ended the agency’s once-popular headquarters tour, and since the Oklahoma City bombing some have questioned the FBI’s proximity to neighboring streets; a suburban location would offer greater physical security.

Nearby jurisdictions, including Alexandria and Fairfax, Montgomery and Prince George’s counties, are all competing for the billion-dollar building project and the FBI’s workers, the largest economic development prize to come in years. A presentation by the General Services Administration, the government’s real estate agency, drew more than 350 people in January. Each jurisdiction is touting its access to public transit and major highways, yet nearly all the locations under consideration are at least 45 minutes from downtown in Washington’s noxious traffic.

The D.C. suburbs are already filled with spy complexes. Beyond the CIA headquarters at Lang­ley and the National Security Agency headquarters in Fort Meade, there are the unremarked headquarters of the National Reconnaissance Office, the National Geospatial-Intelligence Agency, the National Counterterrorism Center and other covert operations.

The FBI, though, is different. We shouldn’t want to hide our chief law enforcement agency. For four decades it has stood symbolically on Washington’s most important street. It’s not supposed to be covert; it is meant to be a publicly accountable law enforcement agency, front and center as a guardian of our democracy.

Ensuring accountability and trust in its leadership means the FBI must be answerable to the public; it should exist in the public eye, its building open to visitors, its officials close to the oversight of Congress, the Justice Department and the White House. On its best days, the FBI stands as the primary protector of our nation’s security and liberties, though on its darkest days, it has also been one of the greatest threats to our civil liberties. Journalists and congressional staff know how hard it is to get information out of the Hoover Building; things could be worse if its staff is isolated somewhere outside the Beltway.

The existential questions underlying this debate are: How much government should be in our capital, and how accessible should it be? The Justice Department, directly across Pennsylvania Avenue from the Hoover Building, is just as close to neighboring streets. Ditto for the nearby IRS headquarters. As their New Deal-era buildings age, will each relocate to suburban office parks to achieve the street “setbacks” required by the war on terrorism? What other agencies may soon cite “security needs” as part of an effort to gain nicer offices in leafy, university-like campuses?

Since the attack on our consulate in Benghazi, Libya, modern security requirements of government buildings have been much discussed — and lamented. Centrally located embassies — what once were inviting, urban temples of U.S. democracy — have been replaced in recent years with fortress-like suburban compounds that discourage visitors and isolate our diplomats even in the capitals of our friendliest allies. We shouldn’t make the same mistake in our own capital.

Since the Sept. 11, 2001, attacks, the District has become a maze of closed streets, bollards and jersey barriers near some government buildings. In 2010, the Supreme Court closed the bronze doors at the top of its iconic steps in the name of security. In a republican democracy, we shouldn’t fortify our government, or the public, right out of the capital. Being in the capital should be a sign of importance and respect.

The Hoover Building must be replaced, but keeping the FBI headquarters downtown is critical to ensuring that our government operates in public view. This is an achievable goal: Two major federal law enforcement agencies — Immigration and Customs Enforcement and the Bureau of Alcohol, Tobacco, Firearms and Explosives — have built new headquarters in the District in recent years.

The FBI is seeking less space that is better utilized: The Hoover Building is 2.4 million square feet, and developers have been told the new headquarters should contain 2.1 million. Rebuilding the FBI where it is on Pennsylvania Avenue would be disruptive in the short term, but it would ultimately be an important sign for our security-conscious capital. Barring that, the agency should move to one of the several D.C. sites Del. Eleanor Holmes Norton has identified.

If we can’t keep our nation’s primary domestic security agency safely in the capital, what can we keep safe in Washington?