Unlike the average offering of found-footage filmmaking, Joel Anderson’s debut Lake Mungo limits the amateur aesthetic now deemed a signature of this genre. The characters aren’t taping themselves or their story in real time, but rather they are being recorded post factum by a documentary crew, including Anderson as the off-screen interviewer. The director/writer as well as John Brawley, the associate producer and director of photography, had the know-how for imitating true crime documentaries; that mimicry — everything from talking head interviews to authentically made but fictional news footage — is key to this film’s power of persuasion.

Calling this film Lake Mungo is confusing when realizing the catalyst for the story, the drowning of 16-year-old Alice Palmer (Talia Zucker), occurs at Norval Dam in Ararat. Lake Mungo, a dry lake in National Mungo Park, doesn’t even come up until around the one-hour mark. Of course, that...