In most jurisdictions, claiming mental illness as a defense in a criminal trial does not necessarily require the defendant to admit guilt. However, the requirements and procedures can vary depending on the country and its legal system.
In some cases, a defendant may choose to use an insanity defense, which asserts that they were not criminally responsible for their actions due to a mental disorder at the time of the offense. To use this defense, the defendant typically needs to demonstrate that they did not understand the nature and quality of their actions, or they were unable to distinguish right from wrong because of their mental state.
It's essential to note that employing an insanity defense can be a complex legal strategy, and it doesn't guarantee that the defendant will be acquitted or found not guilty. The standards for insanity vary across jurisdictions, and the burden of proof usually falls on the defendant to demonstrate their mental incapacity during the commission of the crime.
The process and rules surrounding mental illness and criminal defenses can differ based on the country and legal system, so it's crucial for anyone facing legal issues to consult with a qualified attorney who is knowledgeable about the specific laws in their jurisdiction. They can provide proper legal advice tailored to the individual's circumstances.