In general, it is very difficult for a defense lawyer to convince a judge that the client is mentally incompetent to stand trial. Nevertheless, a lawyer could use this strategy if the defendant has a verifiable serious mental health disorder. Another possibility would be to ask for leniency in sentencing in a plea bargain with the prosecuting attorney.

Even if the defendant was not yet diagnosed when the crime was committed, a criminal defense attorney might still be successful in this effort. However, one or more psychiatrists would need to verify that this individual has a disorder causing severe effects on mental competency.

Psychiatric Evaluations

The chances of having a judge accept a defendant as being mentally incompetent are best if the person's medical history already documents a severe condition. However, if the defense lawyer suspects the client has one of these disorders, at least one psychiatrist must conduct an evaluation and confirm the mental health problem. 

When a judge rules a defendant is mentally incompetent, this person cannot be convicted. Still, the judge can rule that the defendant be committed to a psychiatric facility for a minimum time frame. This is particularly likely if the offense was violent.

Psychotic Conditions

The psychotic conditions of bipolar disorder and schizophrenia may make a person incompetent to stand trial or understand that the alleged criminal behavior is against the law. When these conditions are not effectively controlled by medication, behavior can be impulsive and erratic. The individuals may act because of delusions or following instructions during auditory hallucinations. 

Kleptomania

Psychiatrists, clinical psychologists, and forensic psychologists also might diagnose mental disorders that are not psychotic but are still implicated in problematic behavior. For instance, kleptomania is categorized as a form of obsessive-compulsive disorder. The person experiences overwhelming compulsions to steal and may also be obsessed with hoarding stolen items.

If the defendant is diagnosed with this problem, the lawyer needs a different strategy to persuade a judge to issue a relatively lenient sentence. Courts typically do not recognize individuals with OCD as mentally incompetent. The defendant may feel that the behavior is uncontrollable, but that is not a valid legal defense. The lawyer might advocate for a sentence of probation with a requirement of treatment for OCD. Working out a plea bargain with the district attorney before trial is another option for the defendant with OCD. 

Anyone suffering from a mental health disorder that could be related to criminal activity may contact a criminal defense lawyer for a consultation.