Defense lawyers are scheduled to begin calling witnesses today on behalf of five leaders of an Islamic charity that prosecutors charge was a front for a Palestinian Arab terrorist group, Hamas.

The opening of the defense in the case against the officials of the now-defunct Holy Land Foundation for Relief and Development comes after the prosecution brought its presentation to a federal court jury in Dallas to an unexpectedly early close last week. Prosecutors called just 10 of about 40 individuals disclosed as possible witnesses in pretrial filings.

The prosecution case took just over five weeks, which stands in marked contrast with the 2005 trial in Florida of a former professor, Sami Al-Arian, and three other men accused of acting on behalf of Palestinian Islamic Jihad. In that case, federal prosecutors took nearly five months to build their case. The result embarrassed the government as the jury acquitted Al-Arian on eight counts and deadlocked on nine others.

The new, streamlined approach suggests that prosecutors in the Holy Land case learned some lessons from the Al-Arian trial, where witnesses with no direct knowledge of the alleged crimes sometimes spent days on the stand explaining the function of immigration and tax forms.

The prosecution witnesses, two of whom were Israeli officials who testified using pseudonyms, alleged that the Holy Land Foundation channeled its aid through Palestinian “zakat” committees well known in the community as part of Hamas. Prosecutors also used surreptitious telephone wiretaps and intercepts to argue that the Holy Land Foundation officials were aware of the Hamas ties and sometimes praised the group’s terrorist acts.

Among the highly anticipated witnesses skipped over by the prosecution was a formerly well-connected lobbyist for Muslim causes in Washington, Abdurrahman Alamoudi. Alamoudi, who had ties to Democrats and Republicans, is serving a 23-year prison sentence for a variety of crimes, including plotting with the Libyan president, Muammar Gadhafi, to murder then-Crown Prince Abdullah of Saudi Arabia.

As the defense takes its turn, a former congressman who worked as a lawyer and lobbyist for Holy Land, John Bryant, is expected to be one of the first witnesses called to the stand. Mr. Bryant will explain that federal officials refused to respond to the group’s repeated requests for guidance about which Palestinian charities were considered free of terror ties and which were suspect, court records indicate.

The defense is also expected to call a former American consul general in Jerusalem who later worked as a paid lobbyist for the Palestinian Authority, Edward Abington Jr.

While prosecutors have asserted that the Holy Land Foundation and the charities it supported focused their aid on the children of those killed in terrorist operations against Israel, a defense filing indicates that Mr. Abington will counter that “working with Palestinian zakat committees and supporting the families of ‘martyrs’ along with other Palestinian families was not contrary to United States policy.”

Another witness on the defense list is an associate professor of Middle Eastern and Islamic studies at New York University, Bernard Haykel. Defense lawyers indicated in court papers that Mr. Haykel would opine on the origins of the Egyptian Muslim Brotherhood and its connections to Hamas.

Prosecutors also face a deadline today to respond to an unusual motion from the Council on American Islamic Relations seeking to be removed from a list of unindicted co-conspirators filed in the case. The designation’s only formal significance is to ease the admission of certain prosecution evidence in the case. However, Cair contends that the public filing of the list violated Justice Department regulations and unfairly harmed the Islamic group’s reputation and fund raising.

Some of the witnesses prosecutors did not call in their so-called case in chief could be called later to rebut defense testimony. Prosecutors are not the only ones who may have learned lessons from the Al-Arian case: One of the Holy Land defendants, Ghassan Elashi, is being defended by a former attorney for Al-Arian, Linda Moreno of Tampa, Fla.

In July, the judge in the Holy Land case, A. Joe Fish, issued a gag order barring prosecutors, defense lawyers, and the defendants from speaking with the press.