10 do's and don'ts for obtaining a confession during a police interrogation

Physical coercion, torture, duress, denial of rights, threats and promises of leniency are the poison pills of legally admissible, reliable and voluntary confessions. Obviously we should not engage in such behaviors or any tactics that could render a confession involuntary. This article is intended to assist the professional investigator by outlining statements and techniques that should be avoided so as to ensure the integrity of a subject’s confession.

In August 2016, in the Dassey v. Dittmann case (which was highlighted by the popular Netflix television show, “Making a Murderer”), U.S. Magistrate Judge William Duffin ruled that the guilty verdict returned by a trial jury in 2007 against Brendan Dassey for the murder of freelance photographer Teresa Halbach was based on an involuntary confession that was obtained as a result of constitutionally impermissible promises.

In his order to the State of Wisconsin to either release or retry Dassy, Magistrate Duffin stated, “These repeated false promises [of leniency], when considered in conjunction with all relevant factors, most especially Dassey’s age, intellectual deficits, and the absence of a supportive adult, rendered Dassey’s confession involuntary under the Fifth and Fourteenth  Amendments.”

Also factoring into the finding of involuntariness was the magistrate’s concern that Dassey’s confession may not have been reliable because some of the corroborative details described by Dassey could have been the product of contamination from other sources, including the investigators’ own statements and questioning, or simply logical guesses, rather than actual knowledge of the crime.