A former amusement park worker accused of orchestrating one of the most extensive arsons in state history -- fires that raged through a subdivision under construction in Southern Maryland -- was found guilty of three dozen felony counts on Friday.

Jurors in federal court here deliberated for seven hours over two days before convicting Patrick S. Walsh, 21, of Fort Washington of 35 counts of arson and one count of conspiracy to commit arson in the Hunters Brooke subdivision fires.

The relatively swift verdict was a resounding victory for prosecutors, who brought Walsh to trial with no physical evidence linking him directly to the crime. Key testimony came from Jeremy D. Parady, the confessed driver in the attack on the predominantly black development, who testified as a prosecution witness in exchange for leniency.

Walsh sat motionless, his legs crossed, as the jury's verdict was read aloud. His parents and siblings clutched one another, sobbing quietly, as the foreman pronounced him guilty 36 times. One supporter stalked out of the courtroom as the verdicts were read.

Outside the courthouse, Walsh's supporters declined to comment on the case. One yelled profanities and pushed a news photographer into a wall.

Walsh is one of five men charged in the fires. Two of the suspects, including Parady, have pleaded guilty, and two others are awaiting trial. Judge Roger W. Titus set Walsh's sentencing for Dec. 5 and said the other convicted defendants probably will be sentenced on the same date.

The fires, before dawn Dec. 6, damaged or destroyed two dozen unoccupied houses at Hunters Brooke, an upscale development in Indian Head, about 30 miles south of Washington. The discovery of accelerants in 11 additional homes indicated that the arsonists intended the path of destruction to be wider still, prosecutors said during Walsh's trial.

Prosecutors Donna C. Sanger and Timothy Atkins referred questions to U.S. Attorney Rod J. Rosenstein, who said in a statement: "The jury appropriately evaluated the evidence and held Mr. Walsh responsible for his role in this horrific crime. Although the harm suffered by the victims cannot be erased, it is important that the perpetrators be held accountable."

William B. Purpura, one of Walsh's attorneys, said the jury apparently was swayed by details of his client's activities and interests that Purpura maintained were prejudicial and unrelated to the fires at Hunters Brooke. During the trial, for example, Purpura argued that the government inflated the significance of files found on Walsh's computer equipment that detailed recipes for bombs and terror tactics.

On Friday, Purpura said he had hoped the jury would set those issues aside and focus on the fire itself. "It seems like they didn't," he said.

Sanger and Atkins contended during the trial that Walsh was the leader of the Family, which they described as a gang operating in Charles County. Walsh hoped its members would watch out for one another and be feared by everyone else, they said. Frustrated that the Family was not being accorded the respect he felt it was due, they said, Walsh planned the fires as a display aimed at solidifying the gang's reputation.

"He hoped it would make a name for himself and for the Family," Sanger said in her opening remarks. "The trick was to have it known among his peers [who was responsible] but to not get caught."

Parady's testimony last week was among the most direct evidence linking Walsh to the fires. Parady said he served as a driver and monitored a police scanner while Walsh and others raced from house to house, setting the fires.

Yet Parady also admitted that he lied to investigators, perjured himself under oath in an earlier court hearing and consumed two six-packs of beer and "no more than" six shots of rum in the hours before the fires were set.

In part because the suspects are white and most of the homeowners at Hunters Brooke are black, the fires fueled a perception that racism persists in Charles County. Although he denied in his testimony that he is racist, Parady admitted when he pleaded guilty in April that he targeted the development because a large number of black people were buying homes there.

Reacting to the verdict, Jacque Hightower, a black resident of Hunters Brooke, said he felt that justice was served. Hightower, a government employee, said his house was burned just days before he and his family were to move in. The house was rebuilt, and they have recently moved into Hunters Brooke.

"My family and I," he said, "we dealt with it. We can't let this run our lives or rule our lives. We have to move on. We have careers, children, more important things than some knuckleheads out there doing things they probably don't even understand, as young as they are."

Family members leave federal court after Patrick S. Walsh, 21, was found guilty of conspiracy and multiple counts of arson for planning and helping set more than two dozen fires at the Hunters Brooke development.Patrick S. Walsh is one of five men charged in the arsons.