Dozens of reporters and camera crews lined the street outside the small two-story home with dark red shutters and white plastic siding.
Diane Ivins has not spoken to the media gathered outside her home. "While understanding the job that you guys have to do, she just doesn't want to be bothered," Frederick Police Department Det. Sgt. Bruce DeGrange said after he spoke to her.
"She seemed fine," he added. "She's a little upset about the attention, but she seems fine."
In regards to the anthrax case, which has frustrated government investigators for years, FBI Director Robert Mueller said in a recent interview with ABC News that he was confident the case would be solved.
"We've made progress in the investigation -- I'm comfortable that the investigation is on course and that ultimately it will be successful," Mueller said.
But there have been major missteps in this case, and the FBI has thought it was close before.
In June, the government settled a lawsuit with another scientist from Fort Detrick, agreeing to pay Steven Hatfill nearly $6 million amid allegations he was unfairly targeted and humiliated by leaks to the press. In August 2002, then-U.S. Attorney General John Aschcroft named Hatfill as a person of interest in the mysterious mail attacks, but he has never been charged in connection with the case.
As for the ongoing investigation into the attacks, the anthrax task force is currently comprised of 17 FBI special agents and 10 U.S. Postal Service inspectors. As part of the probe, known as "Amerithrax," investigators have "executed approximately 75 searches and conducted more than 9,100 interviews in the relentless pursuit of the perpetrator of these attacks," according to the Justice Department.
The bureau has not commented extensively on the investigation, but in the fall of 2006, FBI scientist Doug Beecher, a member of the bureau's Hazardous Materials Response Unit based at the its laboratory at Quantico, Va., wrote in an article that no specialized equipment or specialized knowledge of bioengineering was needed to pull off the 2001 attacks.
Beecher's article, which appeared in the journal Applied and Environmental Microbiology, is a rare example of the FBI disclosing information on the anthrax investigation.
According to Homeland Security officials, President Bush occasionally asks how the investigation is proceeding during his morning intelligence briefing.
ABC News' Jason Ryan contributed to this report.