Part 3 | Understanding the Insanity Defense in South Carolina – Guilty, But Mentally Ill Explained

This is the final post in our series on the insanity defense in South Carolina.

In Part 1, we talked about competency — whether someone understands what’s happening in court today and can help in their own defense. In Part 2, we looked at criminal responsibility — whether they understood right from wrong at the time of the crime.

Now we’re turning to the final part of the insanity defense — what happens when a person did understand right from wrong, but because of a mental illness, couldn’t control their actions.

That’s what South Carolina law calls Guilty, But Mentally Ill, often shortened to GBMI.

What “Guilty, But Mentally Ill” Means

“Guilty, But Mentally Ill” is a unique verdict in South Carolina’s criminal justice system.

It means the defendant is legally responsible for their actions — they knew what they were doing was wrong — but because of a mental illness, they couldn’t control their behavior or “conform their conduct” to the law.

On the insanity defense spectrum, GBMI may land somewhere in the middle. 

On one end, there’s Not Guilty by Reason of Insanity (NGRI), which applies when a person couldn’t understand right from wrong at all. On the other, there’s a standard guilty verdict, with no recognition of mental illness.

GBMI sits between the two. It acknowledges mental illness while maintaining accountability.

How a GBMI Verdict Happens

A GBMI verdict can result from a trial or a plea agreement.

At trial, it may come after a judge or jury hears evidence of the person’s mental health — typically through expert testimony and forensic evaluations — and determines that while they were ill, they still met the legal definition of responsibility.

In other cases, it’s the outcome of negotiations between the defense and the prosecution, especially when the evidence shows significant impairment but not complete insanity. In all cases, expert testimony is necessary for a finding on Guilty But Mentally Ill.

As trial lawyer Erin Bailey often explains it, “It’s sort of the option in the middle — one that recognizes mental illness without excusing it.”

A Real Example: State v. Richard Inman (2022)

One of the clearest examples of a Guilty, But Mentally Ill outcome came from one of our own cases: State v. Richard Inman (2022).

Richard Inman suffered from structural brain damage that severely affected his frontal lobe — the part of the brain responsible for impulse control and judgment.

Despite clear evidence of this impairment, the law didn’t allow a full insanity defense. But through careful presentation of medical and forensic evidence, Erin’s was able to secure a GBMI plea.

In her case reflection, Erin explained that this plea and the supporting evidence convinced the judge to issue a lesser sentence than what Inman would have otherwise faced.

Inman’s case remains one of the few where this outcome was both appropriate and impactful. It didn’t erase his responsibility, but it helped the court understand his condition and tailor a more just sentence.

What Happens After a GBMI Verdict

A GBMI verdict doesn’t keep someone out of prison — it mainly changes how their sentence begins.

After sentencing, the defendant is first sent to the South Carolina Department of Corrections (SCDC) mental health hospital for evaluation and treatment.

They undergo a mental health assessment and receive care as needed. Once stabilized, they’re typically moved into the general prison population. Only those with the most serious, ongoing needs remain in specialized treatment for an extended time — and even that’s rare.

Guilty but mentally ill ensures that the Department of Corrections provides some level of treatment, but it doesn’t keep people in hospitals long-term. Most are transferred out in a matter of weeks.

What GBMI Does — and Doesn’t — Do

It’s easy to misunderstand what this verdict actually accomplishes.

What it does:

• Recognizes the role of mental illness in the offense.

• Requires an initial evaluation and treatment through SCDC’s mental health system.

• Allows mental health evidence to be considered during sentencing.

What it doesn’t do:

• It doesn’t replace incarceration.

• It doesn’t guarantee ongoing mental health care once someone is moved to general population.

• It doesn’t carry the same protections as a NGRI finding.

The verdict ensures a baseline level of treatment — but the quality and duration of that treatment may vary significantly.

Why It Matters

Even though a GBMI finding rarely changes how much time someone serves, the process of getting there still matters.

Presenting mental health evidence provides context — it helps the court see the full picture of the defendant’s life, history, and treatment efforts.

As Erin explains it, “Guilty but mentally ill doesn’t help out my clients a whole lot, but the evidence that gets you there can be powerful mitigation.”

In other words, the outcome may not erase punishment, but it can influence how the court perceives the person behind the case — and that may make a meaningful difference.

Why Experience Matters

These cases require more than legal skill — they demand an understanding of both criminal procedure and forensic psychiatry.

An attorney must know how to:

• Coordinate with forensic evaluators and mental health professionals.

• Interpret complex psychiatric reports.

• Present expert testimony clearly and effectively in court.

• Work with prosecutors and judges who may have different levels of experience handling mental health defenses.

Local experience is also key. Each South Carolina circuit handles GBMI cases differently — from which evaluators are used to how judges prefer to handle sentencing.

Understanding those local processes may make the difference between a case that gets lost in the system and one that results in a fair, informed outcome.

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Final Thoughts

Guilty, But Mentally Ill is a narrow path — one that recognizes mental illness without removing accountability. It’s not a loophole or a sidestep from consequences.

But in the right circumstances, it can provide something critical that’s often missing in criminal law: context. It allows the court to see the human story behind the crime — and to balance justice with understanding.

If you or a loved one are facing criminal charges and believe mental health may be a factor, get in touch with the Erin Bailey Law team today.

Every case is unique, and prior results do not guarantee future outcomes.