FBI Director James Comey at the bureau’s Salt Lake City office during a national tour of FBI offices. (AP Photo/Rick Bowmer)

A central tussle  in the tug-of-war between Maryland and Virginia officials over where to relocate the FBI headquarters is where members of the FBI headquarters staff actually live.

The FBI has largely been mum on the issue, allowing the General Services Administration, which manages real estate for the federal government, to conduct a search for a new headquarters site on its behalf. The GSA has not disclosed information on where FBI employees live or how long their commutes are.

Senators from both states have stepped into the void, claiming the FBI staff would prefer to work in their states. When the GSA announced the finalist sites would be Greenbelt, Landover and Springfield, Sen. Mark Warner (D-Va.) said that the FBI would prefer to be close to the FBI crime lab in Quantico, which is about 25 miles down Interstate 95 from the Springfield site.

“On the facts, in terms of where the FBI employees would like to be, access to Metro, access to Quantico, we’re a clear winner,”  Warner said.

Sen. Benjamin Cardin (D-Md.) issued a stern retort: “Wrong, wrong, wrong, wrong,” he told the Post’s Ed O’Keefe. “Most of the percentage of the workers of the FBI live in Maryland. Check their facts.”

Where does Cardin get his facts? From a previously unreleased 2012 study on the possible economic benefits of the FBI relocation by the Maryland Department of Business and Economic Development. Researchers used Census data to get an idea of where FBI officials lived and found a plurality in Maryland. An excerpt:

Based on commuting data of the Census block groups of the current FBI location, we estimate that 43.2% of current FBI headquarters employees reside in Maryland, 33.4% in Virginia and 17.4% in DC.  Outside of Washington DC, the largest number of commuters resides in Montgomery County (16.4%), Prince George’s County (16.3%) and Fairfax County (15.4%).

The researchers also included a map with possible locations of FBI employees’ homes:

That’s a pretty wide spread, but the location of FBI employees’ homes is important for a couple of reasons. First, the data could give one location a leg up on the others. It could also help the region collectively plan to accommodate a federal campus serving 11,000 staff in a way that minimizes traffic congestion.

But from an income tax standpoint, there may not be much to be gained by luring the FBI because, as the report points out, there is little guarantee that the FBI’s employees would actually move to the state where they work, at least in the short-term.

“The only way that Maryland would gain income tax revenue from FBI employees would be if they relocate from either D.C. or Virginia,” wrote the Maryland researchers, in their report. “Currently, 75 percent of workers around the FBI headquarters commute from within a 25-mile radius and would be unlikely to relocate. Very few of the current FBI workers would be likely to relocate to Maryland in the near term.”

Follow Jonathan O’Connell on Twitter: @oconnellpostbiz