Wiretaps obtained under a Patriot Act provision aimed at gathering foreign intelligence wrongly helped convict Muslim immigrants in a domestic criminal case, defense lawyers argued yesterday in U.S. appeals court in Philadelphia.

The lawyers represent five young men convicted of plotting a deadly strike at Fort Dix, N.J. A federal jury in Camden convicted the men - Mohamad Shnewer, Serdar Tatar, and brothers Dritan, Eljvir and Shain Duka - in 2008 of conspiring to kill U.S. military personnel at Fort Dix. All but Tatar are serving life terms.

Prosecutors charged that the Philadelphia-area residents had taken training trips to the Poconos and scouted out Fort Dix.

The three-judge appeals panel had agreed to hear arguments about the constitutionality of the wiretaps under the Foreign Intelligence Surveillance Act, as it was amended by the Patriot Act.

Justice Department lawyers argue that other U.S. courts have upheld the searches, which are authorized not by a federal magistrate, but by a specially created FISA court. High-level Justice Department officials must first certify the need for the wiretaps for national-security purposes.

U.S. appellate judges hearing the case also debated whether U.S. District Judge Robert Kugler was right to let prosecutors play videotapes to the jury showing beheadings. The tapes did not relate to any of the defendants.

A defense attorney argued that jurors turned against his clients after seeing the tapes, although the actual beheadings were not shown in court.

The judges did not indicate when they would rule.

Four of the defendants had attended public high school in Cherry Hill. The men include Shnewer, a Jordanian-born cab driver; Tatar, a Turkish-born convenience-store clerk; and the Dukas, ethnic Albanians from the former Yugoslavia who had a roofing business.