Federal agents investigating arson fires that devastated a subdivision under construction in Southern Maryland in December executed new search warrants yesterday, according to local authorities and residents of a home that was searched.

Waldorf resident John Buckley said three FBI agents accompanied by a deputy from the Charles County sheriff's office scoured his home on Garner Avenue for four hours. Buckley said that his adult daughter was acquainted with some of the five men charged in the fires at Hunters Brooke, the state's largest residential arson in recent memory, and that she spent time with them at the Denny's restaurant where authorities have said a plan to torch the subdivision first took shape.

Buckley declined to identify his daughter but said she was not involved in the fires. There was no indication that the woman is a target of the investigation, which has included interviews with numerous acquaintances of the suspects.

Buckley said the agents left empty-handed.

"They left because they ran out of stuff to look at, not because they found what they were looking for," he said in an interview at his home.

Sheriff Frederick E. Davis confirmed that his office was "assisting [the FBI] with some search warrants." Davis said he did not know how many locations were targeted or what the agents were seeking.

An FBI spokesman declined to comment yesterday, saying the investigation was continuing.

The searches come less than a month after Aaron L. Speed, a former security guard at the subdivision, pleaded guilty to a felony and, in exchange for leniency, agreed to cooperate with authorities investigating the fires. Speed was the second suspect to plead guilty in the case; charges against the other three are still pending.

Speed, 21, has admitted that he was driven by anger toward his employer and resentment toward the affluent, educated homeowners who were moving into Hunters Brooke. Another defendant, Jeremy D. Parady, also 21, pleaded guilty in April, saying the development was targeted because a large number of black people were buying houses there.

Staff researcher Bobbye Pratt contributed to this report.

Investigators comb through the wreckage of one of 26 homes damaged in an arson attack in December at the Hunters Brooke development in the Indian Head area of Charles County.