What Is Forensic Psychology? Its Impact on Our Legal System

By Dr. Matthew Loux and Bryce Loux  |  08/05/2025

Forensic psychology examines human behavior through the lens of the legal system. It explains what we know about the criminal mind, can predict criminal behavior, and influences the legal process.

You might be wondering, “What exactly do forensic psychologists do, and why does our criminal justice system count on them so much?” To answer these questions, it is necessary to consider how forensic psychology affects the U.S. legal system.

Forensic Psychology and Its Role in the Legal System

Forensic psychology involves the use of mental health knowledge and psychological theories to legal issues. The American Board of Forensic Psychology says that “forensic psychology is the application of the science and profession of psychology to questions and issues relating to law and the legal system.”

In criminal cases, forensic psychology practitioners work to provide a court with helpful context about the mental states of the involved parties and may offer expert testimony during legal proceedings. For example, a forensic psychologist might explain whether a defendant knew right from wrong before, during or after the period when a crime was committed.

In addition, forensic psychologists may conduct psychological evaluations regarding civil matters. For instance, a forensic psychologist’s child custody evaluations may be important in custody battles.

Applications for Forensic Psychology

Forensic psychologists can provide psychotherapy to crime victims. In addition, their roles may involve a wide range of other duties, which can include:

• Performing criminal competency evaluations – Forensic psychologists may assist courts in assessing alleged offenders. They help determine whether defendants have the mental capacity to stand trial, understand the trial process, confer with legal counsel, and follow the judge’s orders.
• Conducting forensic evaluations to determine mental state at the time of offense (MSO) – These tests can indicate whether offenders experienced temporary insanity or lost their grip on reality while committing a crime. If a forensic psychology practitioner concludes that a defendant clearly suffered temporary insanity, a judge might order psychiatric treatment rather than prison time.
• Completing threat assessments – Psychologists are often consulted to determine the likelihood that criminals will commit crimes again, especially when prisoners seek parole.
• Delivering expert witness testimony – Forensic psychologists play a key role in trials. When courts appoint them, they speak about issues like broken confessions, shaky eyewitness memories, and the impact of trauma on the human psyche.
• Assisting with child custody cases – In family legal battles, forensic psychology practitioners may interview each parent and child to help the court develop an appropriate custody plan.
• Evaluating prospective jurors – During the jury selection process, some forensic psychologists team up with lawyers to help identify potential hidden biases in jurors.
• Providing psychiatric care for inmates – Some forensic psychologists work in correctional facilities, where they oversee inmates’ psychiatric treatments. These professionals help build individualized care plans to address everything from mental illness to substance abuse.

Forensic Psychology vs. Criminal Psychology

Most people assume forensic psychology and criminal psychology are the same, but these two fields are quite distinct. Criminal psychology examines the minds of criminal offenders to figure out why they act the way they do. A criminal psychologist might use criminal profiling techniques to identify patterns indicative of criminal behavior.

forensic psychology practitioners, on the other hand, work closer to courtrooms. They perform mental-health checkups and testify in trials. Forensic psychologists may also provide recommendations for settling issues like custody disputes.

Common Tools Used in Forensic Psychology

Forensic psychology practitioners combine clinical psychology with courtroom know-how, using various tools such as:

• Clinical assessments – These evaluations can provide meaningful context about an individual’s mental state as it pertains to the complaint.
• Standardized tests – These tests supplement the findings from psychological assessments. Some common examples of tests that forensic psychologists administer include the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) personality quiz and the Wechsler Adult Intelligence Sale (WAIS) IQ test.
• Risk assessments – These assessments help judges understand the likelihood that a criminal will commit a crime again. For instance, the Static-99R is an assessment that indicates how likely a sex offender is to hurt someone again.
• Collateral interviews – This type of interview involves talking to the family, friends, or coworkers of a defendant or plaintiff. They help to confirm or challenge official claims.

Forensic psychologists may share their findings formally in written forensic reports.

The Ethical and Legal Challenges That Forensic Psychologists Face

The role of a forensic psychology practitioner is unique in that it blends medicine and law. Gathering information for a court poses various ethical and legal challenges. For instance:

• Staying neutral is hard when one side pays the fee. Experts must train themselves to relay the facts and not just speak for the client.
• Confidentiality shrinks since warnings or new evidence heard during an exam can land on a judge’s desk later.
• To keep their judgment clear, forensic psychologists need to avoid wearing more than one hat. For example, a forensic psychologist acting as a counselor shouldn’t also test or evaluate clients.

Obtaining informed consent is also a must for professional psychology practitioners who work in the legal system. People who undergo psychological assessments need to know exactly what a test does and why, and be aware that nothing they say will remain private.

Fortunately, there are rules and resources to help with tricky situations, such as the Daubert standard and the ethics guide published by the American Psychological Association (APA).

Real-World Examples of Forensic Psychology

Looking at real-world cases provides a clear picture of how forensic psychology works. There are several famous defendants where forensic psychology practitioners played an important role, including:

• John Hinckley Jr. (1981) – After Hinckley shot at President Reagan, his trial became a national spectacle and Hinckley’s lawyers argued that he was not guilty by reason of insanity. The trial sparked fierce debate about the insanity plea.
• Andrea Yates (2001) – Yates was found guilty of drowning her five children, but a later review showed she had severe postpartum psychosis. A jury ultimately declared her not guilty by reason of insanity.
• Jodi Arias (2013): In this high-profile murder trial, forensic psychologists talked about Arias’s reported post-traumatic stress disorder (PTSD) and her shaky love life. Their testimony showed just how much jurors can be swayed by expert voices.

Requirements for Becoming a Forensic Psychologist

Working in the forensic psychology field requires highly specialized knowledge. Licensed psychologists must also demonstrate sharp critical thinking skills, whether they’re counseling crime victims or providing expert witness testimony.

Degrees 

Most forensic psychology practitioners hold a doctoral degree in psychology. They typically have either a Doctor of Philosophy (Ph.D.) or a Doctor of Psychology (Psy.D.).  

Licensing

Each state establishes licensing requirements for clinical psychologists. Becoming a forensic psychologist and obtaining licensure may also require a specified number of supervised clinical hours, depending on the location.  

Board Certification

Forensic psychologists can obtain board certification from the American Board of Forensic Psychology or the American Board of Professional Psychology. Becoming board-certified signifies that a psychologist not only understands human behavior but also has advanced knowledge of psychological principles.

Where Do Forensic Psychologists Work?

Although forensic psychology is a specialized field, there are various settings where forensic psychologists play important roles. These settings include:

• Courts
• Jails
• Private practice, such as forensic consulting firms
• Legal practices
• Government organizations, such as the FBI, DEA, and local law enforcement agencies
• Psychological research labs at colleges and universities

The Future of Forensic Psychology

Due to the dynamic nature of technology, social science, and legal precedents, forensic psychology is always evolving. As this field continues to change, new and emerging developments include:

• Digital forensics analyses of online posts, cyberbullying evidence, and other examples of people’s digital footprints when cases go to court
• Neurological tests, scans, or other brain checks that legal professionals may reference to support their clients’ arguments
• Trauma-informed practice, which explains how trauma can skew the perspective of a victim or defendant
• Artificial intelligence (AI) software that spots behavior trends, although people still argue about the ethics of using AI in a forensic setting

Technology and the Expanding Role of Digital Forensics

Technology has changed many fields, including forensic psychology. As digital tools continue to advance, forensic psychologists will need to adapt to new changes and stay up to date with these tools. In fact, forensic psychologists’ duties have already begun to expand. Some of their newer responsibilities include:

• Conducting reviews of cybercrimes – Forensic psychology practitioners work with investigators to assess the thoughts and feelings of cybercriminals. They apply their knowledge of psychological principles and online disinhibition (the way people act much braver or meaner in the digital environment).
• Analyzing digital behavior – AI tools now help experts analyze chats and posts to spot concerning behavior. When these tools identify potential threats, forensic psychologists team up with cybersecurity professionals to conduct further analyses.
• Reviewing evidence from social media content – Judges and juries hear about tweets, Facebook® posts, and search histories a lot these days. Psychologists now strive to figure out what online behavior says about one’s moods, friendships, or violations of the law.

Forensic Psychologists Will Always Have an Important Role in Our Legal System

Forensic psychology makes it possible for courts and law enforcement officers to understand people. Though the field is always growing and changing, it will remain inseparable from our legal system.

Forensic psychology practitioners are instrumental in showing judges when a trial is truly fair and guiding ex-offenders back to society. Ultimately, these experts have the power to tip the balance toward justice.

The B.S. in Criminal Justice at APU

For adult learners interested in studying forensic psychology and criminal profiling, American Public University (APU) offers an online Bachelor of Science in Criminal Justice.

Courses examine a broad scope of topics, including criminal profiling, criminal law, and ethics in criminal justice. Other courses include crime analysis, constitutional law, and criminalistics. also discuss how psychological expertise applies to forensic contexts and helps solve criminal cases. This criminal justice degree also offers a digital forensics concentration covering topics such as cybercrime and various aspects of digital forensics.

For more information about this bachelor’s degree, visit APU’s security and global studies degree program page.

Note: This degree program is not designed to meet the educational requirements for professional licensure or certification in any country, state, province or other jurisdiction. This program has not been approved by any state professional licensing body and does not lead to any state-issued professional licensure.

Facebook is a registered trademark of Meta Platforms, Inc.