The Landline Detective (2020) on Netflix

Plot summary

James "Jimmy" Furuta, retired, has set aside a Monday to sort thirty years of family photographs into neatly categorized albums. Among the photographs he comes across a Polaroid dated 1982 showing a car he once owned and later sold to his brother-in-law. That date places his brother-in-law somewhere other than where he had claimed to be on the night his wife, Jimmy's sister-in-law, was murdered. The brother-in-law had returned from a fishing trip to find her dead. Jimmy picks up the phone and calls the people connected to the old tragedy, trying to close a case that has gone unsolved for thirty-five years.