The New York State Appellate Court is hearing the appeal of a former Elmira Jackals hockey player convicted in a murder for hire plot.

Thomas Clayton was found guilty of first- and second-degree murder in 2017 for hiring another man, Michael Beard, to kill his wife in 2015. It was a case that gained national attention and was even profiled on ABC's "20/20."

Clayton filed for an appeal in October.

Attorneys presented their arguments to a panel of justices in Rochester on Wednesday morning. The appeal is based on multiple issues, including claims of insufficient evidence and problems with the discovery process.

Clayton's attorney, Brian Shiffrin, questioned expert testimony from a prosecution witness who tracked cell phone location data. He claims that expert, Sy Ray, was hired at the last minute, and documents were not turned over to the defense until well into the trial.

That didn't give the defense enough time to bring its own expert to refute the findings, which it claims were unscientific.

"Cell tower locations, there's no dispute, are admissible,” Shiffrin said. “What Mr. Ray did wasn't that. Indeed, I pointed out, he came up with not only inaccurate results, but impossible results putting the phones in places they could not have been, and he ended up acknowledging some of that."

"The courts have said visually plotting geolocation data is not new science, it's not new evidence,” said Chemung County District Attorney Weeden Wetmore. “The data that he relied on from Google, from Verizon, from AT&T, had all been admitted without objection."

No date has been set for a ruling in the appeal. Clayton and Beard are both currently serving life sentences.