But at a hearing in April, these crucial claims were debunked by Craig Beyler, a retired fire-safety engineer who reviewed the case for Carver’s legal team.

Beyler said the investigator’s testimony about “alligator charring” and “swirling smoke” was based on ‘80s-era myths scientists have since rejected. He added that the fact that the lab tests were all negative meant that the investigator’s conclusion was “mere speculation.” And the idea that fire cannot travel downward, he explained, was also false.

Beyler said investigators failed to collect enough evidence to rule out electrical causes. He said the blaze’s cause could not be determined. However, he said that scientific testing has shown it would have been impossible for the newspapers to have generated a flame powerful enough to have spread to the building.

Beyler said the fire did not start at ground level, but instead began in the overhang of the alcove where the newspapers were found. The damage to the alcove’s walls was limited. But the fire had so significantly damaged the overhang that pieces of the ceiling were missing. He said the damage to the walls and newspapers could have been caused by “drop-down burning,” which is when flaming debris falls from a higher level of a structure to a lower one.