The Visit (2015)

Plot hole: When they left the camera out overnight to film Nana it would have had to be recording all night. A DSLR will not do this and does not do motion detection either.

Daughter: Mom, there's something wrong with nana and papa.
Mom: They're just OLD.

Trivia: M. Night Shyamalan personally financed the film so that he could have complete creative control over the final product. He wanted to make a low-budget, back-to-basics movie, as he had just finished working on a string of high-budget critical and commercial failures (including "After Earth" and "The Last Airbender") where he had little creative control due to the budgets and studio-mandates. It paid off, as this film, his next film "Split" and his television series "Wayward Pines" were generally considered a "return to form" for Shyamalan by critics.

Question: Why didn't Loretta call 911 instead of just the Masonville Police station when she learned the two people her kids were staying with were not their Grandparents? In the event of two escaped psychopaths holed up in the house with two vulnerable kids, police would have connected the dots with a SWAT team, probably called in to rescue them. Tyler and Becca being in the house with the two unpredictable, deranged killers was basically the equivalent of a hostage situation.