Each charge carries a potential 15-year prison sentence. Sentencing is May 30.

Prosecutors built their case largely around hundreds of FBI recordings of conversations in which Khan expressed support for Taliban attacks and discussed sending about $50,000 to Pakistan.

There were also recordings in which Khan appeared to back the overthrow of Pakistan's government in favor of strict Islamic law, praised the killing of American military personnel and praised the failed 2010 attempt to detonate a bomb in New York's Times Square.

"Despite being an imam, or spiritual leader, Hafiz Khan was by no means a man of peace,'' said U.S. Attorney Wifredo Ferrer, whose office prosecuted the case.

Khan insisted the money he sent overseas was for family, charity and business reasons, above all, his religious school, known as a madrassa, in Pakistan's Swat Valley. Khan also said he repeatedly lied about harboring extremist views to obtain $1 million from a man who turned out to be an FBI informant wearing a wire to record their talk.

"That is not supporting terrorism,'' said Khan attorney Khurrum Wahid in a closing argument. "That is an old guy running a scam, who got scammed.''

Prosecutors, however, said the purported $1 million offer is never heard on any tapes, and no other witnesses testified about its existence. The informant, identified in court papers as Mahmood Siddiqui, did not testify.

Wahid said he will appeal, adding that it's difficult to defend against a broad U.S. terrorism support law.

"It makes me very concerned about whether we still have a First Amendment in this country,'' Wahid said. "Can we say what we feel, or do we now have to be concerned that our words can be criminalized?''

Two of Khan's sons, Izhar and Irfan, were cleared of all charges, and three more defendants have remained free in Pakistan, which does not extradite its citizens to face U.S. criminal charges.

Irfan Khan said after the verdict that his father was mentally unable to express himself clearly on the witness stand.

"I wish he didn't have dementia so he could explain himself better,'' he said. "You're asking him questions about five or six years ago. That really affects things.''

Jurors declined to comment to reporters outside the courthouse.

One of the defendants in Pakistan, Ali Rehman, testified via video link that he was not a Taliban fighter, as U.S. prosecutors claim. He said he handled more than $30,000 in financial transactions for Khan, mainly to invest in a potato chip factory run by Khan's son-in-law.

After Rehman's testimony, Pakistani authorities shut down the video link from an Islamabad hotel to the Miami courtroom, leaving Khan without the testimony of 10 witnesses on his behalf.