One reason the ricochet theory didn’t play a bigger role in the trial was that the federal government prevented it from being fully aired. Key details about the shooting, and the officer’s actions, were only revealed during the trial itself. Prosecution motions and favorable rulings by the judge, a Trump appointee, made it difficult for Song’s lawyers to fully vet the idea or argue that he had acted in self-defense.

And an independent ballistics expert hired by Song’s defense team before the trial was denied access to the defendant in federal prison. As a routine part of any case about a murder or a shooting involving a police officer, said Daryl Parker, the former Marine Corps officer and criminal defense investigator hired by Song’s team, a ballistics expert will meet with an alleged shooter to collect information. Nothing about the Prairieland case, however, was turning out to be routine.

In emails reviewed by The Intercept, Parker and Hayes repeatedly wrote to Federal Medical Center Fort Worth, the federal detention center where Song was held before and during the trial, asking to visit the defendant. All the requests went unanswered. (FMC Fort Worth declined to respond to a request for comment.)

Parker never got a response from the jail official in charge of Song’s detention, let alone visitation rights.

“We sent him everything he asked for,” Parker, speaking publicly for the first time about the case, told The Intercept. “But approval never came.”

It was the first time in his 25-year career that the forensics expert had been denied access to a client in a federal facility.

In the end, members of the jury never received a full airing of the argument nor the multiple pieces of evidence that support it.