"At this point in our investigation, that is the direction we are going," Baarts told CNN.
Baarts said that while investigators are still verifying that information, they believe a felony had been committed in the crash, CNN reported.
He denied rumors that a suicide note had been found at the Harts' Washington house but said investigators were still evaluating some items found at the residence.
Devonte, who is black, earned national attention when a photo of him at age 12 went viral. In the image, the teary-eyed boy embraces a white officer in the middle of a demonstration in Portland, Oregon, related to the fatal police shooting of Michael Brown in Ferguson, Missouri. Devonte had been holding a sign offering "Free Hugs."