NEW YORK—In the winter of 2010, shortly after police discovered the remains of his roommate and three other women buried on a remote stretch of Long Island shoreline, Dave Schaller provided detectives with a description of the person he believed to be the killer.
More crucially, Mr. Schaller told them about his truck.
The man they were looking for was a towering, Frankenstein-like figure with an “empty gaze” who drove a first-generation Chevrolet Avalanche, Mr. Schaller recalled telling investigators. The man’s size stuck out, as did his unusual pick-up truck, which he’d used to flee the house Mr. Schaller shared with Amber Costello….