How Mental Health Defenses Work in Chicago Criminal Cases
Mental health plays an increasingly recognized role in Illinois criminal law. When someone charged with a crime in Chicago has a diagnosed mental health condition or psychological disorder, it can significantly affect how the case proceeds. From investigation through sentencing, mental illness can influence criminal responsibility, competency, and potential sentencing outcomes.
At the Law Offices of Andrew Weisberg, our team understands the complex connection between mental health and criminal defense. As an experienced Chicago criminal defense lawyer, Attorney Weisberg provides compassionate yet strategic representation for clients whose cases involve psychological or emotional disorders.
Illinois Law on Mental Health and Criminal Responsibility
Illinois law recognizes that mental illness can affect whether someone is legally responsible for a crime. The most familiar defense is insanity under 720 ILCS 5/6-2, which applies when a defendant, because of a mental disease or defect, lacked the capacity to appreciate the criminality of their conduct or conform their actions to the law.
This standard focuses on the defendant’s mental state at the time of the alleged offense, not their current condition. A Chicago criminal defense lawyer must present medical and experts’ evidence showing that mental illness prevented the defendant from understanding their actions or knowing they were wrong. When successful, defendants are committed to treatment through the Illinois Department of Human Services instead of serving a prison term.
Illinois also recognizes competency to stand trial under 725 ILCS 5/104-10 et seq., which ensures defendants can understand court proceedings and assist in their defense. If a person is found incompetent, the court pauses the case and orders treatment to restore competency, often for up to a year.
Using Mental Health Evidence to Reduce Criminal Liability
Even when the insanity defense does not apply, mental health evidence can still reduce charges or influence sentencing. One option involves negating specific intent. Many serious offenses, such as first-degree murder or theft, require a particular mental state.
If mental illness prevents forming that intent, charges may be reduced. For example, first-degree murder could be reduced to second-degree murder when mental illness impacts the defendant’s ability to form intent or judgment.
Judges also consider mental illness during sentencing under 730 ILCS 5/5-5-3.1, allowing for alternatives such as probation with treatment instead of incarceration. These approaches promote rehabilitation while maintaining public safety.

Mental Health Courts and Alternative Programs in Cook County
Cook County operates mental health courts that emphasize treatment instead of punishment. These programs provide supervised care and structure for eligible participants while holding them accountable through regular check-ins.
Typical program elements include:
- Comprehensive treatment plans and medication management
- Counseling and case management services
- Ongoing judicial oversight and progress reports
Eligibility often depends on having a diagnosed mental illness linked to the criminal offense and a willingness to undergo treatment. Participants who complete the program may receive reduced charges or case dismissals. A Chicago criminal lawyer can determine eligibility and help advocate for admission into mental health court.
Challenges in Raising Mental Health Defenses
While mental health defenses can be powerful, they also present challenges. Defendants must often undergo court-ordered psychiatric evaluations, which make private medical details part of the court record. In some cases, those found not guilty by reason of insanity may face long-term commitment to a secure treatment facility.
Stigma also remains a factor. Some judges or jurors may have biases about mental illness, which can affect perceptions of the defendant. An experienced Chicago criminal defense attorney must carefully frame the evidence, educate the court, and work with credible psychiatric experts to explain diagnoses and their legal relevance.

Talk to a Chicago Criminal Defense Lawyer About Mental Health and Your Case
If you or a loved one has been charged with a crime while living with a mental health condition, it is essential to have the right legal advocate on your side. The Law Offices of Andrew Weisberg understands how mental illness impacts criminal responsibility, competency, and sentencing options. Our firm has extensive experience working with medical experts, evaluating psychological reports, and pursuing treatment-based resolutions that protect clients’ rights and futures.
A skilled Chicago criminal defense lawyer can evaluate how mental health factors into your situation, identify potential defenses, and work to secure a fair outcome in or out of court. Contact the Law Offices of Andrew Weisberg today at (773) 908-9811 or contact us online to schedule a confidential consultation. Early legal guidance can make all the difference in building a strong defense and accessing the treatment you deserve.



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