Ake v. Oklahoma, 470 U.S. 68 (1985)

The U.S. Supreme Court held that when mental health is a significant factor in an accused person’s defense, they must have the ability to hire an independent expert provided to the defense  at the expense of the state if they cannot afford it. The Court reversed and remanded the holding of the Oklahoma Court of Criminal Appeals and found the denial of psychiatric assistance in Ake’s case was a deprivation of due process and the right of defense counsel to prepare an effective defense. The Court provided the following language in support: 

Meaningful access to justice has been the consistent theme of these cases. We recognized long ago that mere access to the courthouse doors does not by itself assure a proper functioning of the adversary process, and that a criminal trial is fundamentally unfair if the State proceeds against an indigent defendant without making certain that he has access to the raw materials integral to the building of an effective defense. Thus, while the Court has not held that a State must purchase for the indigent defendant all the assistance that his wealthier counterpart might buy, see Ross v. Moffitt, 417 U. S. 600 (1974), it has often reaffirmed that fundamental fairness entitles indigent defendants to “an adequate opportunity to present their claims fairly within the adversary system,” id., at 612. To implement this principle, we have focused on identifying the “basic tools of an adequate defense or appeal,” Britt v. North Carolina, 404 U. S. 226, 227 (1971), and we have required that such tools be provided to those defendants who cannot afford to pay for them. 

“A defendant’s mental condition is not necessarily at issue in every criminal proceeding, however, and it is unlikely that psychiatric assistance of the kind we have described would be of probable value in cases where it is not. The risk of error from denial of such assistance, as well as its probable value, is most predictably at its height when the defendant’s mental condition is seriously in question. When the defendant is able to make an ex parte threshold showing to the trial court that his sanity is likely to be a significant factor in his defense, the need for the assistance of a psychiatrist is readily apparent. It is in such cases that a defense may be devastated by the absence of a psychiatric examination and testimony; with such assistance, the defendant might have a reasonable chance of success. In such a circumstance, where the potential accuracy of the jury’s determination is so dramatically enhanced, and where the interests of the individual and the State in an accurate proceeding are substantial, the State’s interest in its fisc must yield.  

We therefore hold that when a defendant demonstrates to the trial judge that his sanity at the time of the offense is to be a significant factor at trial, the State must, at a minimum, assure the defendant access to a competent psychiatrist who will conduct an appropriate examination and assist in evaluation, preparation, and presentation of the defense.”