When David first meets Katie and he is acting as a plumber, when he is under the sink the left arm of his shirt is wet but when he gets up and puts his vest and jacket on, the shirt is dry.
On Katie's acceptance letter, from medical school, it's addressed to MS. Katherine Marks.
The brown envelope is addressed to Rayburn Senate Office Bldg. There is no such building. There is a Rayburn House Office Building, but none of the 3 Senate office buildings is named for Rayburn.
This film is based on Robert Durst. If he supposedly buried Katherine's body in Pine Barrens then why has it never been found.
When the brown envelope with the ledger which Katie mailed is opened, the postage stamps have no cancellation.
When Katie is in the bathroom after searching through David's office, she lights a cigarette out of a pack of Parliaments but the cigarette she lights isn't a Parliament.
In a nightclub scene that takes place circa 1972, the song Boogie Oogie Oogie plays. This song didn't come out until 1978.
The part of the movie based in Texas was in 2000. The style of Texas license plate on David's SUV was not issued until about 2008.
The opening scene is dated 1971 and features Steely Dan's "Daddy Don't Live in That New York City No More". Steely Dan's first album was released in 1972 (Can't Buy A Thrill) and "Daddy Don't..." was from the Katy Lied album which was released in 1975.
The cigarette lighter David uses to light the joint outside the new apartment is far to modern for the early seventies.
In the New York early 70's part of the movie there's some graffiti seen which belonged to a much later era than this period.
In the shot with the caption for "Galveston 1996", the street shown is lined with houses, curves and travels down hill. There are no hills on the Island.