The Thin Blue Line is a 1988 American documentary film by Errol Morris, about the trial and conviction of Randall Dale Adams for the 1976 shooting of Dallas police officer Robert W. Wood.

Morris became interested in the case while doing research for a film about Dr. James Grigson, a psychiatrist known in Texas as "Dr. Death" for testifying with "100 percent certainty" of a defendant's recidivism in many trials, including that of Randall Adams.

The "thin blue line" in the title "refers to what Mr. Morris feels is an ironic, mythical image of a protective policeman on the other side of anarchy".

In almost every instance, Dr. Grigson would, after examining a defendant, testify that he had found the individual in question to be an incurable sociopath, who he was "one hundred percent certain" would kill again.

[8] In pursuit of creating this idea, Morris sought and received funding for the initial project from the Public Broadcasting Service.

[10] Morris later chose to refocus his research efforts into an investigation on the circumstances of Randall Dale Adams's conviction.

[9] The film presents a series of interviews about the investigation of the shooting of Dallas police officer Robert Wood and a re-enactment of the crime based on the testimony and recollections of Adams, Harris (the actual murderer), the judge presiding over the case (Donald J. Metcalfe), and several witnesses (including Emily Miller and R. L. Miller), as well as detectives (including Gus Rose, Jackie Johnson, and Marshall Touchton).

The film's title comes from prosecutor Doug Mulder's phrase during his closing argument that the police are the "thin blue line" separating society from "anarchy".

[14] Morris has often associated The Thin Blue Line with film noir, further emphasizing its connection to the conventions of fiction filmmaking.

'"[18] Morris's interview style (that of the subject staring directly into the camera) led to a later invention that his wife termed "the Interrotron".

[19] The final scene, in which Morris and Harris are only heard, while shots of a tape recorder appear from various angles, was not originally planned.

The poster for the film gave it the feel of a whodunit, with the tagline: "A softcore movie, Dr. Death, a chocolate milkshake, a nosy blonde and The Carol Burnett Show.

"[33] Roger Ebert gave the film 3.5 out of 4 stars, and wrote that "Morris' visual style in The Thin Blue Line is unlike any conventional documentary approach.

A true story of murder and justice evidently miscarried, wrapped in the fictional haze of a surrealistic whodunit, it will leave you in a trance for days.

"[35] The Thin Blue Line was placed on more critics' top ten lists than any other film of 1988, edging out Bull Durham by one vote.

[42] As a result of publicity around the film, Adams (whose death sentence had been overturned by the U.S. Supreme Court in 1980 and subsequently commuted to life in prison by the Governor of Texas, Bill Clements) had his conviction overturned by the Texas Court of Criminal Appeals,[43] and the case was returned to Dallas County for a retrial.

[44] The district attorney's office declined to prosecute the case again,[45] and Adams was subsequently ordered released as a result of a habeas corpus hearing in 1989.

"[47] Morris, for his part, recalled: "When [Adams] got out, he became very angry at the fact that he had signed a release giving me rights to his life story.

[49] Some scholars believe that by calling the certainty of events surrounding the murder case into question, Morris positions the film as a postmodern text.

Conversely, The Thin Blue Line suggests Adams's innocence by clouding a previously established history.

[51] Stanford Law Review author Richard Sherwin believes The Thin Blue Line actually presents two plots.

Within this notion Sherwin notes sociologist Jean Baudrillard's interpretation of the postmodern media landscape as "flattening" meaning as well as the impossibility of the existence of "truth, authority, and history".

Sherwin argues that for the film to succeed as an affirmative postmodern work, it must contextualize the past events within a present narrative.

He argues that it should take on the challenge, through the clouding of history, of resisting the lure of a narrative and fulfilling "their sworn duty to convict only in the absence of reasonable doubt.

In The Thin Blue Line, it was of all-consuming importance to figure out who was driving that car; who pulled the gun out from underneath the seat, who shot the cop.