Defense attorney Francis Courbois argued that prosecutors rushed to judgment and did not have any evidence linking Owen to the fatal fire.
He said the verdict “surprised” him.
“We thought we were in the running for an acquittal,” Courbois said.
Owen was facing two counts of first-degree murder and one count of first-degree arson.
District Judge Kenneth C. Watson asked jurors before their deliberations to consider first-degree manslaughter and third-degree arson as lesser-included counts if prosecutors failed to prove the other charges beyond a reasonable doubt.
Jurors deadlocked after five hours of deliberation, but Watson encouraged them to continue deliberating.
“I think it was definitely a compromise verdict,” Assistant District Attorney Jennifer Chance said. “Sometimes juries compromise when they have trouble reaching a verdict.”
The prosecutor said she believed the defendant's young age played a significant role in the verdict.
“Huge,” she said. “That's one of the reasons it took us four days to a get a jury.”