Hannah Thompson, 17, was on the run ... On Oct. 26, 2016, Cati Blauvelt, his wife of just a few months, had been found stabbed to death, her body left in a concrete box in an abandoned farmhouse.

We found Cati's body inside that box ... Traveling with him was Hannah Thompson, his new girlfriend, all of 17. Peter Van Sant: How concerned were you about Hannah's safety?

Hannah Thompson, once a teenage runaway ... attention after the murder of 22-year-old Cati Blauvelt, who was found stabbed to death in an abandoned farmhouse in Simpsonville, South Carolina ...