The jury unanimously found all aggravating factors existed in all murders - Chad committed or encouraged the murders for his own personal benefit, the murders were particularly heinous and cruel, he showed no regard for human life, and he is at risk of committing more crimes if he were ever to get out. Chad did not present any mitigating factors, so no mitigating factors outweighed the aggravating factors.
My personal feelings aside, hard to argue with all that :/ Lori was not the first person he tried this schtick on, she was just the first taker for his "We've been married in multiple lives, we have a glorious purpose" scam. He would do it again, and would do so with no remorse. He was eerily nonchalant throughout the trial - even Lori reacted negatively to images of the bodies. He seemed mildly bored.
