Confessions and Forensic Confirmation Bias

Should you waive your rights?

NEVER - police interrogate people they already believe are guilty

The Interrogation

• Create a desire to escape

  • Place a suspect in small, bare, windowless room

  • Begin by making a confident accusation of guilt

  • No legal time limit; possibility of sleep deprivation

• Suspects are in highly vulnerable psychological states

  • Tactics for increasing psychological vulnerability

    • Repeated, unending, cycle of accusations

    • Suggestions regarding leniency

Maximization

• Instill hopelessness, imply harsh punishment absent confession

  • “You will be much better off if you talk to us”

Minimization

• Provide a way out, minimize seriousness of offense

  • “I can understand why you would’ve been upset”

Factors that Increase Vulnerability of a Suspect

• Youth of suspect

• Low intelligence of suspect

• Lack of a clear memory of the event in question

Key Tactic Often Used by Interrogators

• Can lie or “bluff” about evidence

• Including claims of false evidence

Types of false confessions

1. Voluntary

2. Compliant

3. Internalized

Compliant Confession

Confessing to merely get out of the interrogation

Internalized Confession

After long hours and coercive lies from police, people begin to believe that they have committed the crime

Kassin & Kiechel (1996) - Computer Crash Paradigm

• Reaction time task (press “ALT” key and computer crashes

• Manipulated vulnerability and false evidence

  • Computer always crashes (do they confess?)

• No false evidence - 35% confessed (slow pace) and 65% (fast pace)

• With false evidence - 89% confessed (slow pace) and 100% (fast pace)

Russano et al., 2005 - Cheating Paradigm

• Some are induced to “cheat” while others are not

  • Both true and false confessions, unlike computer crash paradigm

• Implying or directly promising leniency increases true and false confessions

  • Comports with concepts of minimization/maximization

Perillo & Kassin, 2011 - Corroboration Inflation

• Evidence “bluffs” increase false confessions via belief in future exoneration

• Indications that confessions impact other types of evidence

  • Hasel & Kassin (2009) – eyewitnesses

  • Kukucka & Kassin (2012) – handwriting

  • Kassin et al (2013) – fingerprint and other forensic “science”

When does a confession have a greater impact?

• A confession has a greater impact on verdicts than eyewitness or character statements (Kassin & Neumann, 1997)

  • 85% of false confession cases that went to trial resulted in conviction (Drizin & Leo, 2004)

How does recording help the situation?

• Police: fewer coercive tactics, improved diagnosis of guilt

• Juries: better at determining guilt with whole transcript

  • Police reports sometimes omit important details

• Suspects: None

  • Being aware of camera didn’t affect likelihood of confession or conviction

Confirmation Bias

• The tendency to seek out, select, and/or interpret information in ways that support existing beliefs

• Ignore or discount evidence that disconfirms

What can motivate confirmation bias?

The desire to:

• be accurate

• reach a specific conclusion

Forensic Confirmation Bias

• The class of effects through which an individual’s preexisting beliefs, expectations, motives, and situational context influence the collection, perception, and interpretation of evidence during the course of a criminal case

Evidence & Confirmation Bias

• Belief in suspect’s guilt influences judgements of handwriting evidence

• Belief in suspect’s guilt influences judgement of inconclusive polygraphs

“Linear” vs. “Circular” Investigations

• Determine suitability of sample prior to any knowledge/exposure to comparison

• Allow reassessment only with firm justification and documentation

Blind Testing

• Do not allow for knowledge about relevant case

• Use an evidence lineup

  • Less suggestive

  • Reduce effect of contextual information

  • Can figure out error rate

Step 1 of a Plea

Defense attorney (if the defendant has one) and prosecutor meet, at which time either attorney (usually prosecutor) suggests a plea bargain

Step 2 of a Plea

Defendant is informed of the plea bargain. If the defendant agrees to the terms of the prosecutor’s offer, s/he proceeds to a plea colloquy

Step 3 of a Plea

Judge makes sure the defendant understands all agreements and waiver of rights (waived rights include: right to a jury trial, right to confront accusers, etc.)

“Shadow of the trial” model - Redich et al., 2017

One should plead guilty if offered sentence is equal to or less than the expected value of the trial (Trial sentence x Potential conviction)

• Example:

  • Probability of conviction at trial = .8

  • Sentence if convicted at trial = 10 years

  • Expected value of trial = 8 years

    • Therefore, defendant should accept a plea offer with a sentence of 8 years or less

Trial Penalty Model - Redich et al., 2017

Prosecutors, defenders, and judges form an interdependent workgroup with shared goals such as disposing of cases efficiently and minimizing uncertainty – to this end, the workgroup established norms or going rates for defendants willing to plead guilty

• Defendants who reject these going rates are penalized

Descriptive Theory of Doorholding

P(Doorhold) = Cd + Ct + E - D/Vt - B

• P (probability)

• Cd (characteristics of door holder)

• Ct (characteristics of target)

• E (eye contact)

• D (distance)

• Vt (Velocity of target)

• B (# of bystanders)

Innocence Problem

Sentencing guidelines (e.g. mandatory minimums) may allow for prosecutors to compel false guilty pleas (Dervan, 2012)

Research for Innocence Problem

• Edkings & Dervan (2012)

• Plea Bargaining Simulation Study (Zimmerman & Hunter, 2018)

• Wilford, Zimmerman, Yan, and Sutherland (2021)