Richard Chichakli, the longtime aide to Russian arms dealer Viktor Bout, lost his bid to overturn his conviction on money laundering and conspiracy charges when a federal appeals court in New York rejected his legal complaints.

A three-judge panel of the U.S. Court of Appeals for the Second Circuit ruled last week that Chichakli’s effort to gain a new trial was “without merit.” Chichakli is serving a five-yer prison term.

Chichakli had challenged the use of evidence from a laptop seized from Bout by federal agents during the climax of a sting operation against the Russian in 2008. Chichakli also complained that his trial judge refused to let him call additional witnesses, including a key DEA agent involved in the case.

Meanwhile, lawyers for Bout have mounted a second attempt to overturn his 2011 conviction and subsequent 2012 sentence to federal prison. Bout was convicted on conspiracy to kill U.S. officials and citizens and other charges. He is current serving his term at a medium-security facility in Marion, Ill.

Last month, Bout’s new team of lawyers attacked the credibility of the government’s main witness against Bout, Andrew Smulian, contending he had advance knowledge of the sting operation against the Russian and that his knowledge undercut the prosecution’s conspiracy charges against him.

Bout’s lawyers also quoted the former judge in the Bout case, retired U.S. District Court Judge Shira Scheindlin, who told the New York Times that the 25-year prison term she imposed on Bout was “excessive” and “inappropriate.” Despite those concerns, Scheindlin not only imposed the sentence, she later rejected Bout’s effort to win a new trial.

Bout’s lawyer said that Scheindlin’s comments were important “because they show that the degree of threat that Viktor Bout poses to the world and the United States is insubstantial.”

Federal prosecutors are opposing the new trial effort.