As a Forensic Psychologist, What Should I Know When My Assessment Findings Are Central to High-Stakes Sentencing in Capital Murder Cases?

Capital sentencing is not simply a “bigger” version of other criminal testimony. It is built around the expectation that punishment must be individualized when the death penalty is sought (and when a defendant is facing life-without-parole for an offense committed as a juvenile). Courts routinely call on mental health professionals to help illuminate the kinds of facts that make an individual case meaningfully different from another case that looks similar on paper.

We are often asked to translate complex human development, psychiatric history, neurocognitive functioning, trauma exposure, and institutional adjustment into language that feels usable for a sentencing decision. The risk is that “usable” gets mistaken for “certain.”

The courtroom is emotionally charged, but the science cannot become emotional
Capital proceedings often unfold in a room saturated with grief, moral outrage, fear, and competing narratives of harm. That emotional intensity does not just shape jurors; it shapes how attorneys frame our testimony and how our words land. Our credibility can rise or fall on whether we appear to be doing disciplined forensic work or telling a persuasive story.

We also work inside a broader context of inequity
Capital punishment in the U.S. is inseparable from race and the history of differential punishment. Research emphasizes persistent racial disparities in who is sentenced to death, including patterns tied to the race of the victim and the defendant, and mechanisms like prosecutorial discretion and jury selection practices. This matters for our work even when we are not “testifying about race.” It shapes the ethical and professional reality in which our evaluations operate, systems that may amplify bias. We do not fix that system from the witness stand, but we can avoid feeding it through sloppy inference, overconfident claims, or methods that are not fit for the legal question.

Role clarity is one of the strongest safeguards we have. As forensic psychologists, we are not arbiters of punishment, advocates for either side, or moral commentators. Our task is to provide psychologically grounded, legally relevant assessment findings that assist the court in understanding the individual before it, without drifting into the ultimate legal or moral conclusion the law reserves for the factfinder.

In practice, our findings are often used to speak to issues like: 

• Mitigation (e.g., severe mental illness, developmental trauma, intellectual disability, cognitive limitations)
• Aggravation arguments framed as future risk or institutional violence potential
• Functional capacities (judgment, impulse control, moral reasoning, planning)
• Responsivity to supervision, structure, and treatment

Mental health professionals are called on to help illuminate considerations of moral culpability and specific deterrence in these cases, where boundaries become essential.

A courtroom example: Imagine a penalty phase where the defense is presenting neurodevelopmental history and severe trauma, and the prosecutor’s cross-examination turns sharply: “Doctor, are you telling this jury he should not be held responsible?"

That’s not a clinical question. It’s a boundary test. If we answer like a moral advocate (“No one with that history is responsible”), we’ve stepped outside our lane and invited the court to view our testimony as an argument. If we respond with disciplined role clarity (“Our findings speak to psychological functioning and developmental context; responsibility and sentencing are legal determinations for the jury”), we preserve credibility while still allowing the court to use the information appropriately.

In capital cases, the temptation is to “bring everything.” But the higher the stakes, the more important it is that every tool we use is defensible for the precise question it’s being used to answer. A concrete example comes from the caution against using the PCL-R to assess risk for serious institutional violence in capital sentencing.

Priorities that show up as defensibility later
When assessments may shape sentencing outcomes, process matters as much as conclusions. That typically means:

• Comprehensive records review across medical, educational, developmental, psychiatric, and correctional domains
• Multiple methods and multiple sources (records, collateral data, structured measures where appropriate, careful interview methods)
• Explicit alternative interpretations, especially when the story of the case makes one interpretation feel emotionally “obvious”
• Limitations stated plainly, including when the data cannot support the conclusion counsel wants

Consider an evaluation where records show long-standing psychosis, trauma exposure, special education placement, and early cognitive concerns. In testimony, an attorney asks: “So the trauma caused the murder?”

That phrasing is a trap. If we accept it, we’ve converted a complex developmental risk context into a single causal claim. The more defensible response is to keep the structure of sound evidence visible: what the records show, what the assessment supports, what we can infer probabilistically about functioning (e.g., emotion regulation, threat perception, impulsivity), and what cannot be concluded as a direct causal chain.

This is where “sound evidence” isn’t an abstract ideal—it’s how we prevent the court from using our expertise as a shortcut to certainty.

Assume every methodological choice will be questioned. Capital cross-examination is often exhaustive by design. It’s common to see challenges framed around: 

• bias or advocacy (“You’re here for the defense, correct?”)
• scope creep (“That’s not what that test measures, is it?”)
• certainty inflation (“You’re saying he will be violent again?”)
• moral forcing (“So the jury should spare him?”)

Defensibility does not come from sounding confident. It comes from being able to explain, step by step, how we got from data to conclusion, and where we stopped.

The “reasonable disagreement” moment
A very common cross-examination move is: “Doctor, isn’t it true another reasonable forensic psychologist could look at the same information and disagree with you?”

This question is less about the answer itself than about whether the expert becomes defensive. A credible response acknowledges professional disagreement while redirecting the focus to method and reasoning rather than personal authority.

Below are three ways an expert might respond: two that strengthen credibility, and one that does not.

Response #1: Method-Anchored
“Yes. Reasonable professionals can sometimes disagree. My opinion is based on established forensic methods, a comprehensive review of the record, and how the evidence was evaluated.”

Response #2: Role-Anchored
“Yes. Disagreement can occur. My role is to explain how I reached my opinion, what information I relied on, and why that reasoning is sound.”

Response #3: Defensive (What to Avoid)
“No. Any competent forensic psychologist would reach the same conclusion.”

Defensibility is also about staying out of the prosecutor’s narrative
One of the most subtle risks in capital work is being pulled into the opposing side’s frame. If a prosecutor repeatedly uses emotionally loaded language (“predator,” “monster,” “evil”), and we start answering in that register, we lose scientific distance, and the testimony begins to look like rhetoric. When we keep language precise and functional, we make it harder for anyone to portray our testimony as advocacy dressed up as science.

The jury doesn’t need less nuance; it needs clearer structure
Capital juries and judges may be asked to absorb clinically complex material under emotional strain. Our job is not to “dumb it down.” It’s to make our reasoning trackable. That typically means: 

• plain language definitions of core constructs (psychosis, intellectual disability, executive dysfunction, trauma sequelae)
• separating what is known (records, test results, observed behavior) from what is inferred
• clarifying probability (“elevates risk,” “consistent with,” “supports”) instead of prediction (“will,” “definitely”)

Victim impact statements (VIS) and the emotional ecology of the penalty phase
Even when we are not testifying about victim impact statements, they shape the emotional climate of sentencing. Research on VIS transcripts in capital sentencing notes that these statements are highly varied, often focus on characterizing the victim and the family’s experience, and, importantly, rarely include explicit vengeance or punishment recommendations; sadness was more pervasive than anger, and the degree of emotional language was not particularly high compared to everyday sources.

For us, the practical implication is not a policy argument; it’s a reminder to communicate. The penalty phase contains human emotion regardless, and our credibility often depends on whether we can hold complexity without becoming emotionally performative ourselves.

Aging, dementia, and competency for execution
Some capital-related work arises long after sentencing, including competency for execution questions in older offenders. Madison v. Alabama highlights that amnesia of the offense does not categorically preclude execution, and that the court’s focus should be on functional abilities (not diagnostic labels) when determining competency for execution; the Eighth Amendment bar applies when the individual lacks a rational understanding of why they are being executed, regardless of the cause of the impairment.

This is a powerful example of why communication and framing matter: diagnosis alone is not the endpoint. Courts want function, reasoning, and rational understanding articulated clearly.

As forensic psychologists working in capital sentencing, we occupy a role of extraordinary responsibility. Our assessments may influence the most consequential decisions a court can make. In this context, clarity, and rigor are not constraints, they are safeguards.

Discipline means using methods that fit the question (and resisting tools that do not), keeping inference bounded, and making uncertainty explicit rather than hiding it. It means holding role clarity under adversarial pressure and communicating complex findings in a way that preserves nuance without drifting into persuasion.

And because capital cases can drag on for years, discipline is also a future-oriented practice. A defensible evaluation is one that still makes sense when reread long after trial—when the only thing left on the page is our reasoning.

Training

• Criminal Forensic Assessment Certificate
• Evaluation for High Stake Sentencing Capital and Juvenile Murder Cases
• AAFP: Introduction to Forensic Assessment in Death Penalty Cases
• AAFP: Bind Over-Waiver Evaluations for Juvenile Court
• Juvenile Assessment Issues and Evaluation of Juvenile Waiver to Adult Court
• Evaluation in Non-Capital Federal Sentencing Cases
  

Blog Posts

• Are We Executing Justice? Concerns Over Death Penalty, Mental Disability, and Misapplication
• What not to use in assessing risk for institutional violence: The case against the PCL-R in capital cases
• Capital Punishment and Race
• Letting them speak: Analysis of victim impact statements in capital sentencing proceedings
• The Death Penalty and Mental Illness
• Evaluating competency for execution in older offenders in context of dementia