Attorney Malik Imran Safdar said the prosecution failed to prove its case during the 20-month trial, which was partly conducted in a jail, The New York Times reported Saturday.
"(The men) are feeling so relaxed, so comfortable and so satisfied," he said. "But their families have suffered a lot."
Muhammad Shouaib Mughal, Shahid Hussain, Humbal Akhtar and Fiasal Abbasi were arrested after naturalized American citizen Faisal Shahzad told a federal district court in New York that he received training in explosives during a trip to Pakistan. Those skills and financial support were used in his plot to detonate an explosives-packed sport utility vehicle in Times Square, he said.
All four men denied involvement in Shahzad's plot.
Shahzad pleaded guilty and was sentenced to life in prison without possibility of parole in October 2011.