Scott Walker delayed shooting for 5 months so he could shoot on the cusp of fall, starting with no snow and ending in deep winter. He has said he literally wanted the feel of the weather closing in on the story, freezing the case.
Jack Halcombe is based on retired Alaska State Trooper Detective Glenn Flothe.
When Halcombe is reviewing files in connection to the missing girls, the photos he looks through, and the ones on the wall at the police station later (with the exception of Vanessa's character) are those of the real life victims.
Robert Hansen died August 21, 2014, at Alaska Regional Hospital in Anchorage. He was 75. During the making of this movie, he was still alive.
In the film, Cindy says she left a tampon in her vagina as evidence that she had been raped by Hansen. When she got a chance, she ran to the road and flagged down a passing truck. The driver, Robert Young, had said that for safety reasons he never picks up hitch-hikers and the only reason he stopped for her was because they were in Alaska and she didn't have shoes on. Months later, during Alaska State Troopers investigation, it was discovered that the tampon and Paulson's rape test kit had never been collected by Anchorage police after they first questioned her and Hansen, and so it had not been used as evidence.