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Bar News - January 18, 2013

Criminal Law: Diminished Mental Capacity as a Sentencing Consideration


Diminished mental capacity is well recognized as a mitigating factor in criminal sentencing at the federal level. In the New Hampshire court system, the issue is less clearly defined but can still impact criminal culpability and play a role in sentencing.

In the United States Sentencing Guidelines, diminished mental capacity is defined as “significantly impaired ability to understand the wrongfulness of the behavior comprising the offense or to exercise the power of reason or control the behavior that the defendant knows is wrongful.” There are many synonyms (mental illness, mental condition, etc.), but “mental capacity” is the term consistently used by courts. Diminished mental capacity is not an insanity defense and does not require proof that the defendant lacked criminal intent. US v. Valdez, 426 F.3d 178, 184 (2d. Cir. 2005). Rather, the focus is on the degree to which diminished mental capacity makes the offender less culpable.

In the federal court system, where the sentencing guidelines still play a major role in sentencing, courts most commonly use a three-step approach to sentencing. First, the courts must determine the applicable sentencing range according to a complex process laid out in the guidelines. Gall v. United States, 552 U.S. 38 (2007). Second, once the range is decided, courts determine whether a departure from that range (either upward or downward) is warranted. The guidelines set strict limits on allowable departures. United States v. Jordi, 418 F.3d 1212 (11th Cir. 2005). The third step, applicable since 2005, opens up sentencing as a process to “consider every convicted person as an individual and every case as a unique study in the human failings that sometimes mitigate, sometimes magnify, the crime and the punishment to ensue.” Gall, at 598.

Diminished mental capacity has been recognized both under the guidelines portion of the review and under the third part of federal sentencing, pursuant to18 U.S.C. § 3553(a), which is known as a statutory or “variance” review. Case law created by the federal sentencing process, along with relevant scientific studies indicating mental conditions and factors influencing a person’s ability to distinguish between right and wrong and the ability to control conduct understood to be wrongful, help explain why diminished capacity is an important factor in both state and federal sentencing.

There is no restrictive definition of diminished mental capacity. The nature and impact of various mental disabilities allow lawyers to use the principle as a broad tool to apply against individual circumstances, to explain a client’s actions. The defendant’s individual history and experience help explain why a defendant might be less culpable. Even under the strict sentencing requirements, federal courts have departed in many cases based on diminished capacity arguments. These arguments include Attention Deficit Disorder, Post-Traumatic Stress Disorder, difficult family history, severe learning disabilities, and even self-medication with drugs and alcohol. United States v. Anderson, 04-2709 (1st Cir. June 29, 2006); United States v. Derbes, 369 F.3d 579, 583 (1st Cir. 2004); United States v. Studley, 907 F.2d 254, 258 (1st Cir. 1990); United States v. Menyweather, 431 F.3d 692 (9th Cir. 2005); United States v. Woodley, 344 F. Supp. 2d 274 (D. Mass. 2004) (based on extraordinary rehabilitation in case involving “a deeply troubled young man whose mental illness and addictions were never addressed” and whose “pattern of substance abuse is one of self-medication”); United States v. Pallowick, 364 F. Supp. 2d 923 (E.D. Wis. 2005) (sentencing bank robbery defendant below the advisory guidelines where the defendant “self-medicated” his “severe mental illnesses – major depressive disorder and anxiety disorder with drugs and alcohol).

The rationale used by federal courts concerning diminished mental capacity is that certain mental conditions – whether cultural, biological, or the result of physical disabilities – may make a person less culpable for criminal conduct. Culpability under both federal and state law requires knowledge and free will. To be criminally culpable under NH RSA 626:2, a person must act purposely, knowingly, recklessly or negligently. Scientific studies support the notion that some people are less able to control criminal action and thus less culpable for the action as a result of a mental condition. An FBI study concluded children diagnosed with Attention-Deficit/ Hyperactivity Disorder are as much as seven times more likely than others to develop an antisocial disorder, which supports the assertion that a mental disability can lead to criminal conduct. (Goldstein, ADHD and Implications for the Criminal Justice System, Federal Bureau of Investigations, US Government). Similarly, other studies show that there are much higher drug and alcohol addiction rates and related illicit behavior among children and adults suffering from similar mental conditions.

Under the federal sentencing guidelines, (the first and second parts of federal sentencing) specific limits are placed on the use of diminished mental capacity arguments. If used to justify a lesser sentence, the diminished capacity must “contribute substantially” to the offense. The guidelines also indicate that a diminished capacity argument cannot be used if: (1) the significantly reduced mental capacity was caused by the voluntary use of drugs or other intoxicants; (2) the facts of the defendant’s offense indicate a need to protect the public because the offense involved actual violence or serious threat of violence; or (3) the defendant’s criminal history indicates a need to incarcerate the defendant to protect the public.

The third step of federal sentencing, statutory variance sentencing under 18 USC §3553(a), requires the court to consider the offender’s personal characteristics and history, without limiting specific factors. The word “consider” implies a lower standard, and in practice, courts allow broader arguments. Prior precedent or scientific recognition of a disability appears important in the sentencing process, but the First Circuit has recognized diminished capacity as a legitimate sentencing factor in a variance argument.

The arguments discussed above are equally relevant in the New Hampshire court system. State sentencing laws do not restrict sentencing considerations (NH RSA 651). State law gives judges wide discretion in sentencing, unless a mandatory minimum sentence is involved. Sentencing consideration in both systems is designed to be based on blame or culpability.

How to Make the Argument

Build your own record based on your client’s history and background. Use independent sources of information to tell the client’s story. When possible, document any and all clinical diagnoses. Because sentencing does not involve strict adherence to the Rules of Evidence, your client can authorize you to obtain information from educators, social service agencies, and medical and mental health providers. Use records commonly available or the lack of records to support your argument. Talk to family members, prior school counselors, community mental health providers, and doctors. Look for juvenile records, prior presentence reports, and police records. Obtaining evidence independent of the case can be an extremely effective way of presenting objective information to the sentencing court about the relative culpability of your client.

Ultimately, diminished mental capacity opens a broad area allowing us to humanize our clients. Diminished mental capacity provides an explanation and puts the criminal action in perspective as it relates to that client. It is also a necessary part of helping the judge balance the many sentencing considerations he or she must consider in determining a just sentence.

John T. Pendleton is a partner/owner of Dwyer Donovan & Pendleton in Portsmouth and board president of Seacoast Mental Health Association. He has been representing businesses and individuals in federal criminal matters since 1997 and can be contacted at or through

Anthony Carr is a third-year law student at the University of New Hampshire School of Law. Anthony participated in a part-time externship at Dwyer, Donovan & Pendleton in fall 2012 and can be reached at

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