INTO THE ABYSS
(IFC) Michael Perry, Werner Herzog, Jason Burkett, Jeremy Richardson, Adam Stotler, Sandra Stotler. Directed by Werner Herzog
Michael Perry is a convicted murderer scheduled to die in a Texas prison in just eight days. Master filmmaker Werner Herzog explores every angle that he can of the case, interviewing the convict, relatives of both the victims and the perpetrators, as well as prison officials and a pastor who has given comfort to those about to die in their final hours. It is a fascinating look into the soul of humanity as Herzog asks why do people kill as well as why do people allow states to kill.
See the trailer, clips and web-only content here.
For more on the movie this is the website.
Release formats: Standard
Genre: Documentary
Rating: PG-13 (for mature thematic material and some disturbing images)
Cinema365 
I think theres a mistake because Kristen Willis is not in the film. if you are refearing to Burketts wife her name is Melyssa Burkett. Kristen Willis was the exgrilfriend at the time of the murders, since she was involved in the crimes but left out of the movie i think is a big mistake to include her name
Updated. I went off the cast list on iMDB at the time and had not yet seen the film. Good catch.