ATF investigator testifies no cause found for Ghost Ship fire in Oakland

OAKLAND, Calif. (KGO) -- Just how did the Ghost Ship fire in Oakland start? It's a question that remains unanswered to this day more than two and a half years later and one that the defense wants to use to their clients' advantage.

"They failed to follow the obviously leads," said defense attorney Curtis Briggs. Attorneys for defendants Max Harris and Derick Almena maintain that the deadly fire was intentionally set with a Molotov Cocktail, but ATF investigator Barbara Maxwell testified there was no evidence of a bottle or any indicator of arson found at the scene.

RELATED: Ghost Ship Trial: Witness says Almena laughed at making improvements to warehouse

"What I do know is we have a number of witness that the ATF and City of Oakland had not asked questions of, that say they saw suspicious persons in that warehouse," said Briggs, "that they heard a fight, that they heard-breaking glass. They heard popping noises and they saw people running."

Maxwell maintained there were no witnesses or indicators in the investigation that pointed to arson.

RELATED: Ghost Ship Trial: heartbreaking last texts from fire victims

She did describe a jerry-rigged electrical system in the warehouse, basically a maze of extension cords leading to and from makeshift conduits and outlets.

In the end, Maxwell testified investigators knew where but not exactly how the fire started.

See more stories and videos about the Ghost Ship fire.