The verdict came after about six hours of deliberations, following testimony from, among others, a onetime finance director of a super PAC supporting Mr. Trump; an ex-chief of staff to a former Republican congressman from Texas; and the 2018 Republican candidate for governor of Nevada.
Prosecutors outlined a two-part scheme, saying Mr. Parnas had lied to the Federal Election Commission about certain campaign donations he had made and that he and Mr. Kukushkin had tried to gain favor among candidates with contributions tied to the Russian tycoon, Andrey Muraviev, with whom they were involved in a cannabis business.
“The purpose behind this conspiracy was influence buying,” a prosecutor, Hagan Cordell Scotten, said during closing arguments on Thursday, adding: “The voters would never know whose money was pouring into our elections.”
Throughout the trial, Mr. Bondy presented his client as an enterprising businessman who was a longtime proponent of legalizing marijuana and who also wanted to lead a company that would bring natural gas from the United States to Europe to help prevent a Russian “stranglehold” on energy.
Although Mr. Parnas had strayed beyond his area of expertise, Mr. Bondy said, he had not “willfully” broken any laws. Instead, Mr. Bondy argued, Mr. Parnas had been flummoxed by the intricacies of campaign finance rules.
“He was in well over his head,” Mr. Bondy said. “But he had some good ideas.”
Gerald B. Lefcourt, a lawyer for Mr. Kukushkin, said that his client, too, had lacked “criminal intent” and was not involved in making political donations. Mr. Lefcourt said Mr. Kukushkin had planned to start a legal cannabis business and believed that Mr. Parnas and Mr. Fruman were politically connected experts who could help obtain the necessary licenses.
Instead, Mr. Lefcourt said, the two had taken money meant for business expenses and used it to pay off debts and finance their lavish lifestyles, essentially swindling Mr. Kukushkin.