California residents who are following the trial of James Holmes may be aware that his attorneys have mounted a defense based on insanity. Holmes is accused of killing 12 people and injuring more than 70 others in a Colorado movie theater shooting in July 2012. The insanity defense is used rarely by defense attorneys for a number of reasons, and it may be being mounted in the Holmes case because the defendant is facing the death penalty.
One of the chief drawbacks of an insanity plea is the sanctions associated with this kind of defense. When an insanity plea is successful, the offender is committed to a psychiatric facility with no fixed release date. They will then remain institutionalized until they can demonstrate that they no longer pose a danger to the public. This often results in confinement for life, which can deter defense attorneys as well as their clients.
Another reason that insanity pleas are rare is their poor success rate. This kind of defense is only mounted in about 1 percent of county court cases according to data from the National Institute of Mental Health, and juries only find for the defendant in about a quarter of the cases in which it is used. Juries are often unsympathetic to claims of insanity because this defense is frequently associated with heinous crimes, and the strategy may be viewed as a way of escaping more severe punishment.
Criminal defense attorneys may consider a number of factors when formulating a trial strategy, and developing an approach designed to win over the jury could be a vital part of these preparations. Criminal trials are often decided based on perception as well as facts, and the members of a jury may be more receptive to explanations than excuses. However, if the evidence in a criminal case is compelling and the possible sanctions are severe, an attorney may decide to recommend an insanity plea.