After spending more than seven hours inside, state prosecutors and police emerged from Dixon's house - in Hunting Ridge, along the city's western border with Baltimore County - carrying boxes, folders and a blue cooler they had brought in with them.
The mayor kept to her schedule, and several political allies defended her publicly, but the search - a strong indication that Dixon is at the center of the investigation - had a disquieting effect on City Hall.
Hours after they left the mayor's house, prosecutors served subpoenas on five city employees. "All I can say is that this has been a long investigation, and I have cooperated with the prosecutors," Dixon said last night as she left a scheduled event at the Baltimore Museum of Art. "I am really staying focused on running the city and doing the best we can to move forward."
State Prosecutor Robert A. Rohrbaugh declined to comment.
Investigators have been examining spending irregularities at City Hall since a March 2006 series of articles in The Sun that detailed questions about the role of Dixon - then council president - in approving contracts that benefited her sister's employer. Prosecutors have served subpoenas on the city's development agency, Finance Department and Board of Estimates in the past year.
Two people with ties to Dixon - her former campaign chairman and the owner of a company that employed her sister - have pleaded guilty on tax charges as part of the probe.
But the decision to raid the mayor's private residence, which is not paid for by taxpayer money, represented a more aggressive stance in the investigation, which to date has largely relied on subpoenas to gather documents from city offices and employees.
The search warrant drew criticism from some, including City Councilwoman Mary Pat Clarke - considered by many to be an independent voice on the council - who likened the raid to a "home invasion" and said that the state prosecutor's office should "stop picking on the mayor. ... Leave her alone."
Dixon's lawyer, Dale P. Kelberman, also criticized the prosecutor, calling him "unaccountable." He said the prosecutor's office has spent hundreds of thousands of dollars on investigations that "went nowhere" and suggested this one would also result in no charges. Federal prosecutors spent 18 months investigating hiring, spending and other practices at City Hall but ended their probe without filing any charges.
"The state prosecutor has no limitation on the extent to which he can conduct an investigation of this type except his judgment," Kelberman said. "We leave to the public the verdict on what they think of that judgment."
It is not uncommon for such investigations to drag on as prosecutors build evidence for a case. In Maryland, for instance, the federal investigation of former state Sen. Thomas L. Bromwell took years.
Kelberman and Sterling Clifford, a Dixon spokesman, said they could not say where the search warrant was filed or what prosecutors removed from the house. It was also unclear why prosecutors issued subpoenas yesterday to the five city employees, some of whom worked for Dixon when she was council president.
Those employees are Lauretta Brown, deputy director of the mayor's Office of Constituent Services; Chelsea Scott, a secretary in the mayor's office; Sharon Jackson, an assistant in the mayor's office; Wanda Watts, with the city's Health Department; and Anne Lansey, with the Department of Transportation.
Dixon, a Baltimore native, formally entered politics in 1987 when she won the City Council seat Kweisi Mfume vacated when he was elected to Congress. After serving as council president for six years, Dixon overwhelmingly won the 2007 Democratic primary and general election for mayor.
For months, she has been able to put the investigation aside, focusing instead on city government. The raid comes six months into her new term, which has been defined by a large drop in the number of homicides and an effort to make the city cleaner.
Several political allies - and even former opponents - offered Dixon support yesterday.
"I am convinced she would not jeopardize her incredibly good record as mayor," said state Sen. Lisa A. Gladden, a Baltimore Democrat and Dixon ally. "I say that with much affection because she has been doing a great job. This is old. We just need to move on."
Dixon has been beset by ethical questions since her time on the City Council. She came under fire in 2006 after the series of articles in The Sun documented that she had voted on contracts at the Board of Estimates that benefited her sister's employer - a company called Utech.
Dixon did not file complete ethics forms disclosing her sister's employment until after reports first appeared in the newspaper. Utech's owner, Mildred E. Boyer, pleaded guilty to tax evasion charges in March.
Utech was hired by Doracon Contracting to perform $344,000 of electrical work on a $25 million development known as Frankford Estates. The company was hired shortly after the project received tax breaks from the city and state. Doracon's offices were raided by the state prosecutor's office in November.
The Sun also reported that Dixon's former campaign chairman, Dale G. Clark, had received $500,000 in taxpayer money without a contract when he worked as a computer consultant to the City Council. Clark pleaded guilty to tax charges in September.
Both Boyer and Clark agreed to cooperate with prosecutors, but it was unclear whether that assistance led to the raid on the mayor's home. A lawyer for Clark said his client has not heard from the prosecutor's office in more than a year. An attorney for Boyer declined to say whether his client had been contacted.
On Jan. 11, 2007, the city Board of Ethics decided not to launch a formal investigation into the matter.
Dixon and her two children were present when investigators arrived and entered her home about 6:30 a.m., officials said. Dixon left the house soon after and went to the gym.
She returned shortly after 9 a.m. with her daughter and a City Hall aide. Dixon walked through the front door and did not take questions from reporters gathered on the street. About an hour later, Dixon left her house again and came to City Hall.
About 1:45 p.m., investigators emerged from Dixon's house with a uniformed Maryland state trooper. They removed six boxes and a blue cooler.
Investigators declined to answer questions and drove away in the minivan, an unmarked state police cruiser and another unmarked Chevrolet Malibu.
Byron Warnken, a University of Baltimore law professor, noted that the raid means the prosecutor was able to convince a judge that there was probable cause of evidence of a crime - or the result of that crime - at the house.
He said that while search warrants issued for a private residence tend to get more attention from the public, the legal burden of proof to obtain it is the same for other search warrants.
"Our biggest interest in privacy is in our body and our next biggest interest is in our home," he said. "It doesn't take more or less to get a search warrant for your house or your business."
Sun reporters Kelly Brewington, Julie Bykowicz, Nicole Fuller, Melissa Harris and Tom Pelton contributed to this article.