I Am A Killer Netflix: Polygraph & Confession Evidence

Series History and Production

I Am A Killer is a documentary series that premiered in 2018, produced by Znak & Co. (later Transistor Films) [1]Verified I Am A Killer Series Information
Confirms five seasons released through October 2024 and sixth season in January 2025, total episode counts, and broadcast history on Crime+Investigation and Netflix. The series launched on Crime+Investigation (C+I) in the UK and on Netflix internationally in 2018 [2]Verified I Am A Killer: Netflix & A+E Networks Renew True Crime Series
Confirms the show launched on C+I in the UK and on Netflix internationally in 2018, produced by Znak & Co.. Netflix and A+E Networks' Crime & Investigation renewed the show for a second season in August 2019, picking it up for another ten-part run [2]Verified I Am A Killer: Netflix & A+E Networks Renew True Crime Series
Confirms the show launched on C+I in the UK and on Netflix internationally in 2018, produced by Znak & Co.. Since then, the series has expanded dramatically: Season 3 aired on Netflix in August 2022, Season 4 was released in December 2022, Season 5 arrived in October 2024, and Season 6 — consisting of six episodes — was released on January 8, 2025 [3]Verified I Am A Killer Wikipedia — Season 6 Information
Confirms Season 6 released January 8, 2025 with 6 episodes on Netflix. In total, the series has produced 44 episodes across six seasons [4]Verified I AM A KILLER Season 6 Returns With 6 New Episodes on Netflix
Confirms 38 episodes prior to Season 6, with Season 6 bringing total to 44 episodes. Produced by Transistor Films..

The show takes viewers inside America's death row facilities and maximum-security prisons, offering unfiltered interviews with inmates convicted of murder [5]Verified I AM A KILLER Netflix Official Series Page
Confirms series premise: death row inmates convicted of capital murder giving firsthand accounts. What distinguishes I Am A Killer from other true crime documentaries is its format: each episode centers on a single case, allowing the inmate to tell their version of events in their own words. The filmmakers juxtapose these firsthand accounts with interviews from victims' families, prosecutors, defense attorneys, law enforcement officers, and forensic experts [6]Verified I Am A Killer Season 3: Why everyone's talking about this Netflix doc
Confirms multi-perspective format including prosecutors, defense attorneys, investigators, friends and relatives. This multi-perspective approach creates a layered narrative that frequently challenges viewers' assumptions about guilt, innocence, and the circumstances surrounding each crime.

Why This Series Matters for Understanding Polygraph Evidence

I Am A Killer matters to the polygraph community because it reaches an enormous global audience with narratives that touch directly on how lie detection technology intersects with the criminal justice system. Netflix now has over 301 million paid subscribers worldwide [7]Verified Netflix Subscribers Statistics 2026
Confirms Netflix reached 301.6 million global subscribers as of 2026, available in more than 190 countries [8]Verified Netflix Wikipedia — Global Reach
Confirms Netflix has 325 million paid memberships in more than 190 countries as of 2026, and true crime consistently ranks among the platform's most-watched genres. When shows like I Am A Killer reference polygraph tests — even in passing — they shape public perception about what psychophysiological detection of deception (PDD) can and cannot do.

The stakes are particularly high when the series addresses death penalty cases. Capital punishment cases involve the most severe consequences in the American legal system, and the evidentiary standards, interrogation practices, and forensic tools used in these investigations demand the highest level of scrutiny. When a documentary presents polygraph evidence without sufficient context about its proper use and validated accuracy rates, it can reinforce misconceptions that affect public discourse, jury pools, and policy debates. Understanding the psychological and physiological foundations of polygraph testing is essential for viewers who want to evaluate the series critically.

Investigative Tool vs. Courtroom Evidence

The primary role of the polygraph in murder investigations is as an investigative tool — a method for law enforcement to assess the credibility of suspects, witnesses, and persons of interest during the early stages of a case. Detectives use polygraph results to help determine the direction of their investigation: which leads to pursue, which alibis to verify, and which suspects warrant further scrutiny.

In many of the types of cases featured on I Am A Killer, polygraph examinations occur during the pre-trial investigation phase. Suspects are asked to voluntarily submit to testing, and the results frequently influence subsequent interrogation strategies. When a suspect shows physiological responses consistent with deception, investigators often intensify their questioning, sometimes leading to confessions that become the centerpiece of the prosecution's case.

This distinction between investigative tool and courtroom evidence is crucial but often lost in documentary presentations. Polygraph results are generally not admissible as evidence in most U.S. criminal trials [9]Verified Polygraph Evidence in U.S. Courts
Confirms polygraph results generally not admissible in most U.S. courts; federal courts and about half of states prohibit entirely. The Supreme Court's 1998 ruling in United States v. Scheffer upheld a military evidence rule banning polygraph evidence, and most federal and state courts follow similar restrictions [10]Verified United States v. Scheffer: Supreme Court Ruling on Polygraph Testing
Confirms Supreme Court upheld military per se ban on polygraph evidence; cites studies placing reliability at 85-90%. Some states allow polygraph evidence only with mutual consent from all parties, while states including New York, Texas, Pennsylvania, and Illinois find polygraph tests completely inadmissible [11]Verified Admissibility of Polygraph Tests in Court
Confirms NY, TX, PA, IL, and DC find polygraphs completely inadmissible. Despite this, confessions made during or after polygraph examinations remain admissible as long as the actual test results are not presented to the jury [12]Verified Polygraphs, Plethysmography, and Witness Credibility — NC PRO
Confirms confessions made during/after polygraph testing are admissible if actual test results are not presented to jury. For a broader look at how polygraph evidence functions in court systems, see our guide to polygraph evidence in Ontario criminal courts and private vs. court-ordered polygraph differences.

How Polygraphs Function in Capital Case Investigations

In capital cases specifically, polygraphs serve several distinct functions throughout the legal process. During suspect screening, polygraphs help detectives narrow down a pool of suspects by testing individuals' denials of involvement. As confession catalysts, the post-test interview — the conversation between examiner and suspect after the polygraph charts are scored — has historically been a point at which suspects make admissions or full confessions [13]Verified Countering confessions induced by the polygraph: Of confessionals and psychological rubber hoses
Foundational research on how polygraph examinations function as instruments for inducing confessions.

Polygraphs are also used for witness verification, testing the truthfulness of key witnesses whose testimony could determine whether a case results in conviction. Defense attorneys sometimes commission private polygraph examinations of their clients to guide legal strategy, though they are under no obligation to disclose unfavorable results. In some jurisdictions, polygraph results play an informal role in plea negotiations, potentially influencing whether prosecutors pursue the death penalty. Post-conviction, inmates sometimes take polygraph tests as part of innocence claims, appeals, or clemency petitions.

Legal scholars have argued that courts should admit polygraph evidence in the penalty phase of capital trials specifically, noting that U.S. Supreme Court precedent establishes that expansive rules of evidence govern the penalty phase [14]Verified Mitigating Evidence? The Admissibility of Polygraph Evidence in Capital Cases
Argues courts should admit polygraph evidence in penalty phase of capital trials under expanded evidentiary rules. However, this remains a contested area of law. Understanding these functions provides essential context for evaluating how I Am A Killer portrays the role of polygraph testing in the cases it profiles.

Cases Where Confessions Drove the Narrative

While I Am A Killer does not dedicate entire episodes to polygraph testing, the themes of truth, deception, and the reliability of confessions run throughout all six seasons. Multiple episodes feature cases in which law enforcement administered polygraph tests during investigations or in which confession reliability is directly contested.

Several notable episodes illustrate these dynamics. David Lewis, profiled in Season 1, unreservedly admitted to killing a 74-year-old woman while burglarizing her house, but his defense team maintained that he was mentally incompetent to make voluntary confessions [15]Verified I Am a Killer Episode List
Confirms individual episode details including David Lewis and Robert Shafer case summaries. Robert Shafer killed two men after kidnapping them and boldly confessed to the crime, yet was unable to explain his motivations [15]Verified I Am a Killer Episode List
Confirms individual episode details including David Lewis and Robert Shafer case summaries. These cases raise fundamental questions about what makes a confession reliable — questions that connect directly to the science of psychophysiological detection of deception.

The show also features cases where inmates maintain their innocence despite confessions, where co-defendants offer contradictory accounts, and where the physical evidence does not clearly align with the confession narrative. These episodes highlight the complexity of truth-finding in criminal investigations and the limitations of any single tool — including polygraph testing — in determining guilt or innocence. For a deeper exploration of how deception manifests in these narratives, see our analysis of overly detailed stories as indicators of deception.

The I Am A Killer: Released Spinoff

The series also spawned a spinoff — I Am A Killer: Released — which follows convicted killer Dale Sigler after his parole following 30 years in prison after being sentenced to death [16]Verified I AM A KILLER: RELEASED Netflix Official Page
Confirms spinoff series about paroled death row inmate Dale Sigler making a stunning confession. The spinoff, which aired in 2020, explores what happens when a death row inmate re-enters society and subsequently makes a stunning confession [16]Verified I AM A KILLER: RELEASED Netflix Official Page
Confirms spinoff series about paroled death row inmate Dale Sigler making a stunning confession. This spinoff directly engages with the psychological dynamics of delayed confessions and the question of why someone might agree to take a polygraph test or make incriminating statements long after their original trial.

How Post-Test Interviews Generate Confessions

One of the most significant intersections between polygraph testing and cases like those featured in I Am A Killer involves post-polygraph confessions — statements made by suspects during the post-test interview phase of a polygraph examination. This phenomenon has deep implications for both polygraph practice and criminal justice.

A standard polygraph examination consists of three phases: the pre-test interview (where the examiner discusses the issues and formulates questions), the in-test phase (where physiological data is collected), and the post-test interview (where results are discussed with the examinee). It is during the post-test interview that many confessions occur. Furedy and Liss (1986) examined how polygraph examinations could function as what they described as psychological instruments for inducing confessions, drawing attention to the dynamics of the post-test confrontation [17]Verified Criminal Interrogation and Confessions
Confirms the 1962 manual formalized the Reid Technique's nine-step interrogation process linked to polygraph examination outcomes.

The psychological mechanisms at work during post-polygraph confessions include perceived futility of denial (when told a scientific instrument has detected their deception, suspects may believe continued denial is pointless), authority compliance (the formal testing environment triggers compliance-based confession behavior), and minimization tactics (some examiners suggest that confessing will lead to more lenient treatment). Fred Inbau's foundational 1962 manual on criminal interrogation formalized the Reid Technique's nine-step interrogation process and linked polygraph examination outcomes directly to psychological interrogation strategy [18]Verified Understanding False Confessions
Confirms confessions were judged honest more frequently than denials; observers systematically failed to identify false confessions. This text became the standard practitioner reference for integrating polygraph results into interrogation approaches.

Research has also demonstrated that observers systematically fail to identify false confessions because confessions are judged as honest more frequently than denials, and people lack a perceived motive for deception in confession scenarios [19]Verified On the psychology of confessions: Does innocence put innocents at risk?
Confirms innocent suspects waive Miranda rights at 81% vs 36% for guilty suspects; interrogators exert more pressure on innocent suspects. This finding has significant implications for how juries evaluate confession evidence presented in capital cases like those profiled on I Am A Killer.

When Confessions Are Challenged

Defense attorneys in capital cases frequently challenge post-polygraph confessions on several grounds. They argue that the confession was involuntary because it was obtained under duress or following coercive interrogation tactics. They challenge the reliability of the polygraph results that preceded the confession. They point to inconsistencies between the confession and physical evidence. And they raise concerns about the suspect's mental state, intellectual capacity, and understanding of their rights.

Saul Kassin's groundbreaking research has shown that innocent suspects waive their Miranda rights at a rate of 81% compared to 36% for guilty suspects, and that interrogators exert significantly more pressure on innocent suspects due to confirmation bias and guilty-expectancy effects [20]Verified Innocence Project Research Resources — False Confession Data
Confirms approximately 25% of exonerated individuals had confessed and 11% had pleaded guilty. This creates an especially dangerous dynamic: the very people most in need of legal protection are the ones least likely to exercise their rights. Understanding the psychology that drives suspects to cooperate — or resist — during interrogations is crucial for evaluating the confession evidence presented in true crime documentaries. For more on the forensic psychology behind these dynamics, explore the work of Bruce Bongar on forensic psychology's bridge to polygraph.

The relationship between polygraph results and confessions continues to be one of the most debated topics in forensic science and criminal law, as evidenced by the ongoing scholarly discourse covered in our analysis of The Jinx and Robert Durst.

The Scale of the False Confession Problem

Perhaps the most sobering intersection between polygraph testing and the cases profiled in I Am A Killer involves the possibility of false confessions. The Innocence Project reports that approximately 25% of individuals exonerated through DNA evidence had confessed to crimes they did not commit, and 11% had pleaded guilty [21]Verified Innocence Project Exonerations Data
Confirms 29% of Innocence Project client exonerations involved false confessions (current as of Feb 2026). Their current data shows that 29% of their client exonerations involved false confessions [22]Verified The Problem of False Confessions in the Post-DNA World
Confirms 80%+ of false confessions occurred in homicide cases; 81% of proven false confessors who went to trial were convicted. More than 80% of documented false confessions occurred in homicide cases — exactly the type of cases profiled in I Am A Killer — and a staggering 81% of proven false confessors who proceeded to trial were convicted by juries despite their later proven innocence [23]Verified False confessions
Confirms Kassin's three types of false confessions (voluntary, compliant, internalized) and key risk factors.

Saul Kassin, a leading researcher in false confession psychology at John Jay College of Criminal Justice, introduced the foundational taxonomy that distinguishes between three types of false confessions [24]Verified False Confessions Fact Sheet — Age Demographics
Confirms 63% of false confessors were under age 25; roughly 25% of DNA exonerations involved false confessions. Voluntary false confessions are given without external pressure, often motivated by a desire for attention, mental illness, or a misguided desire to protect someone else. Compliant false confessions are made to escape an aversive interrogation situation, often by suspects who believe they can prove their innocence later — this is the type most commonly associated with polygraph-related confessions [24]Verified False Confessions Fact Sheet — Age Demographics
Confirms 63% of false confessors were under age 25; roughly 25% of DNA exonerations involved false confessions. Internalized false confessions are made by suspects who come to genuinely believe they committed the crime, often after prolonged and suggestive interrogation [24]Verified False Confessions Fact Sheet — Age Demographics
Confirms 63% of false confessors were under age 25; roughly 25% of DNA exonerations involved false confessions. Youth and individuals with intellectual disabilities are particularly vulnerable, with 63% of documented false confessors being under 25 years of age [25]Verified APA Polygraph Validity Research — Meta-Analytic Survey
Confirms 89% accuracy for single-issue diagnostic testing (CI 83%-95%); 85% for multi-issue testing (CI 77%-93%); 38 studies, 3,723 examinations.

Polygraph Testing and False Confession Risk

The relationship between polygraph testing and false confessions is an important area of study. Proponents of polygraph testing point to the APA's 2011 meta-analysis, which found that validated single-issue diagnostic techniques produced an aggregated decision accuracy of 89% (with a confidence interval of 83%-95%), based on 38 qualifying studies involving 3,723 examinations [26]Verified Accuracy of polygraph techniques: Problems using confessions to determine ground truth
Documents methodological concerns about confession-based field studies where criterion and test outcome are not independent. Multi-issue techniques produced an accuracy of 85% (confidence interval 77%-93%) [26]Verified Accuracy of polygraph techniques: Problems using confessions to determine ground truth
Documents methodological concerns about confession-based field studies where criterion and test outcome are not independent. These figures demonstrate that properly administered examinations using validated techniques provide strong diagnostic value.

However, William Iacono's research has highlighted methodological concerns about confession-based field studies, arguing that when confessions are used as the criterion to determine ground truth, the criterion and test outcome are not independent, potentially inflating apparent accuracy [27]Verified Distinguishing true from false confessions using physiological patterns of concealed information recognition
Confirms true confessors showed larger physiological responses to correct vs incorrect answers; false confessors showed no differential responding. This doesn't diminish the practical utility of polygraph testing but does highlight the importance of proper testing protocols and qualified examiners.

Recent innovative research by Linda Geven (2020) offers a promising new approach: using physiological patterns of concealed information recognition to distinguish true from false confessions. Her proof-of-concept study found that true confessors showed larger physiological responses to correct versus incorrect answers, while false confessors exhibited no differential responding, successfully distinguishing genuine from false admissions of guilt [28]Verified False Confessions: Causes, Consequences, and Implications
Confirms three sequential errors producing false confessions: misclassification, coercion, and contamination; confession evidence uniquely potent in biasing fact-finders. This research points toward exciting developments in using polygraph technology not just for deception detection but for confession verification.

Richard Leo's comprehensive analysis identifies three sequential errors that systematically produce false confessions: misclassification of innocence, guilt-presumptive accusatory interrogation with deception and coercion, and contamination through post-admission narrative shaping [29]Verified Police-induced confessions: Risk factors and recommendations
Confirms false confessions result from interactions between situational pressures and individual vulnerabilities; AP-LS white paper. Leo found that confession evidence is uniquely potent in biasing fact-finders toward conviction, making these errors particularly consequential in capital cases.

The landmark Kassin et al. (2010) white paper on police-induced confessions, published in Law and Human Behavior and approved by the American Psychology-Law Society, found that false confessions result from interactions between situational pressures (excessive interrogation time, false evidence, minimization tactics) and individual vulnerabilities (juveniles, intellectual disability, mental illness) [30]Verified Polygraph examination of a serial killer with sexual motives
Foundational research examining polygraph examination in a serious criminal case context. For readers interested in the ongoing scientific debate about polygraph methodology, our analysis of Minnesota's polygraph science innovators and the CQT debate provides additional context.

What the Series Does Well

I Am A Killer deserves credit for several strengths in its approach to criminal justice storytelling. The series presents multiple perspectives on each case, including defense attorneys, prosecutors, law enforcement, and the inmates themselves [6]Verified I Am A Killer Season 3: Why everyone's talking about this Netflix doc
Confirms multi-perspective format including prosecutors, defense attorneys, investigators, friends and relatives. It allows viewers to hear confession narratives firsthand and evaluate credibility on their own terms. The show raises important questions about the reliability of interrogation-based evidence and draws attention to systemic issues in criminal investigations.

The series' factual accuracy regarding individual case details is generally strong. The producers work with court records, law enforcement files, and first-person interviews to reconstruct each case. When the show references that a suspect was given a polygraph examination or made a confession, these facts are typically verifiable through public records. The outcomes of cases — convictions, sentences, and appeals — are accurately reported.

Similar to other true crime productions we've analyzed — such as Polygraph on Forensic Files and the celebrities caught lying in famous polygraph cases — I Am A Killer successfully brings forensic and legal topics to a broad audience. The series has consistently performed well on Netflix's global top 10 charts since Season 3 [4]Verified I AM A KILLER Season 6 Returns With 6 New Episodes on Netflix
Confirms 38 episodes prior to Season 6, with Season 6 bringing total to 44 episodes. Produced by Transistor Films..

Where the Series Falls Short on Polygraph Science

Where I Am A Killer falls short is in the details and context surrounding polygraph examinations and confession evidence. A typical documentary reference might state that a suspect 'failed a lie detector test' without explaining that polygraph results were not presented to the jury, that the term 'failed' is an oversimplification of a complex scoring process involving validated test data analysis methods, or that the subsequent confession may have been influenced by the psychological pressure of the testing environment.

The show rarely discusses examiner qualifications, the specific type of polygraph technique used (such as the Backster Zone Comparison Test), or the scoring methodology — all of which are critical to evaluating the reliability of any polygraph result. It also compresses the timeline between polygraph testing and confessions, creating an impression of seamless progression from testing to truth-telling. In reality, the process involves complex legal and psychological dynamics that deserve more nuanced treatment.

The series typically does not explain that polygraph results carry different weight depending on the technique used. The APA's meta-analysis found meaningful differences between single-issue techniques (89% accuracy) and multi-issue techniques (85% accuracy) [26]Verified Accuracy of polygraph techniques: Problems using confessions to determine ground truth
Documents methodological concerns about confession-based field studies where criterion and test outcome are not independent. Without this context, viewers may draw inaccurate conclusions about the weight and reliability of polygraph evidence in capital cases. For a deeper understanding of what actually happens during a polygraph examination, visit our complete guide to PDD.

The treatment of confession evidence also deserves more context. As research on how true crime books portray polygraph tests has shown, media portrayals of forensic science consistently oversimplify complex processes, and documentary series are no exception.

The Legal Landscape

Understanding polygraph admissibility is essential for viewers of I Am A Killer who want to grasp how the evidence presented in the show actually functions within the legal system. The legal framework for polygraph evidence in the United States is complex and varies significantly by jurisdiction.

The foundational case is United States v. Scheffer (1998), in which the Supreme Court upheld a military evidence rule banning polygraph evidence, finding that the per se rule served three legitimate interests: ensuring admission of only reliable evidence, preserving the role of court members in assessing credibility, and avoiding collateral litigation [10]Verified United States v. Scheffer: Supreme Court Ruling on Polygraph Testing
Confirms Supreme Court upheld military per se ban on polygraph evidence; cites studies placing reliability at 85-90%. The Court's opinion noted that studies place polygraph reliability at 85% to 90%, while critics cite figures around 70% [10]Verified United States v. Scheffer: Supreme Court Ruling on Polygraph Testing
Confirms Supreme Court upheld military per se ban on polygraph evidence; cites studies placing reliability at 85-90%.

New Mexico remains unique in making polygraph evidence generally admissible without prior stipulation [10]Verified United States v. Scheffer: Supreme Court Ruling on Polygraph Testing
Confirms Supreme Court upheld military per se ban on polygraph evidence; cites studies placing reliability at 85-90%. Most other states either prohibit polygraph evidence entirely or allow it only under specific conditions. Federal courts and approximately half of U.S. states prohibit polygraph evidence entirely [9]Verified Polygraph Evidence in U.S. Courts
Confirms polygraph results generally not admissible in most U.S. courts; federal courts and about half of states prohibit entirely. For a detailed comparison of how different jurisdictions handle polygraph evidence, including the landmark Canadian case that influenced Commonwealth law, see our analysis of R. v. Béland.

In the penalty phase of capital trials, some legal scholars argue for expanded admissibility. Legal commentary published in the UC Davis Law Review argues that lower courts incorrectly apply Scheffer's analysis to the penalty phase, where different and more expansive rules of evidence should govern because of the heightened due process requirements in death penalty proceedings [14]Verified Mitigating Evidence? The Admissibility of Polygraph Evidence in Capital Cases
Argues courts should admit polygraph evidence in penalty phase of capital trials under expanded evidentiary rules. This debate has particular relevance to I Am A Killer cases where polygraph evidence could potentially influence sentencing decisions.

How Documentaries Shape Public Perception

Netflix's enormous platform — with over 301 million subscribers across 190+ countries [7]Verified Netflix Subscribers Statistics 2026
Confirms Netflix reached 301.6 million global subscribers as of 2026 [8]Verified Netflix Wikipedia — Global Reach
Confirms Netflix has 325 million paid memberships in more than 190 countries as of 2026 — means that true crime documentaries like I Am A Killer reach audiences that far exceed those of any academic journal or legal proceeding. When these programs reference polygraph testing, even in passing, they shape public perception about what lie detection can and cannot accomplish.

The true crime genre on Netflix has expanded dramatically in recent years, with series like Forensic Files, Making a Murderer, and The Confession Tapes all touching on themes of interrogation, confession reliability, and forensic evidence. Each of these programs presents an opportunity to educate viewers about the real science behind these tools — and each carries the risk of oversimplification.

For viewers of I Am A Killer who want to understand how polygraph portrayals in media compare to professional reality, we recommend exploring our analyses of polygraph testing in soap operas, true crime YouTube channels and polygraph fact-checks, and TikTok polygraph trends. For a comprehensive look at how the printed word handles these topics, see how true crime books portray polygraph tests and polygraph in crime novels vs. professional reality.

The history of lie detection itself provides valuable context for evaluating modern portrayals. From the earliest methods of lie detection in ancient China to the pioneering work of Hans Gross in criminology and the Reid and Inbau partnership that defined American interrogation, the evolution of deception detection has been a story of continuous scientific advancement.

Critical Viewing Guidelines

Viewers of I Am A Killer can enhance their understanding by keeping several principles in mind while watching. First, when the show mentions that a suspect 'failed' or 'passed' a polygraph test, recognize that this is a simplification. Polygraph results involve numerical scoring on validated scales, and the accuracy varies by technique — from 89% for single-issue tests to 85% for multi-issue formats [26]Verified Accuracy of polygraph techniques: Problems using confessions to determine ground truth
Documents methodological concerns about confession-based field studies where criterion and test outcome are not independent.

Second, understand that a confession made during or after a polygraph examination does not automatically validate the polygraph result or confirm the truth of the confession. Research consistently shows that the dynamics of interrogation — including the psychological pressure created by polygraph testing — can produce both true and false confessions [30]Verified Polygraph examination of a serial killer with sexual motives
Foundational research examining polygraph examination in a serious criminal case context. As Ryszard Jaworski's study on the polygraph examination of a serial killer with sexual motives demonstrates, even in the most serious criminal cases, the relationship between polygraph results and the truth is complex and requires careful professional interpretation.

Third, remember that the legal admissibility of polygraph evidence varies dramatically by jurisdiction. What is used as an investigative tool may never reach a jury. The confessions that result from polygraph examinations, however, frequently do reach juries — making the conditions under which those confessions are obtained critically important.

Finally, consider seeking out the primary sources. The peer-reviewed studies cited in this article provide a far more nuanced picture than any documentary can offer. For those considering whether to take a polygraph test themselves, understanding why someone who is lying might agree to a polygraph and whether you can retake a polygraph after an inconclusive result are valuable starting points.