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.
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.