The following excerpt is from Editor Elizabeth Kelley's new book, Representing People With Autism Spectrum Disorders: A Practical Guide for Criminal Defense Lawyers. The book is a compilation of expert opinions examining the experience of people with ASD in the criminal justice system.

"An experts opinion is only as good - and persuasive- as the information he/she used to form it. Some of that information is out of the attorney’s control; it depends on the expert’s education, experience, and research. Nevertheless, some of that information comes from the attorney through record gathering and other efforts.

The attorney (or investigator) should gather pertinent records, such as school records, medical and psychiatric records, and records from any residential treatment placements. The attorney will likely want to consult with the ASD expert to identify other relevant materials and determine whether the expert should interview family or friends as part of the evaluation. Particularly if the client has never been diagnosed with ASD before, obtaining supporting records and information that predate the offense will bolster the reliability of the expert’s conclusion. In most cases, the attorney will want to provide the ASD expert with all available evidence about the crime, including police reports and witness interviews.

After the expert has reviews relevant discovery and records, he/she will almost certainly need to interview the client, and perhaps friends and family as well. ... The client and other interviewees should clearly understand the purpose of the evaluation and limits of confidentiality. Although the expert will certainly explain this at the time of the interviews, preparing the client beforehand avoids unnecessary confusion. Explaining the importance of the evaluation - and the importance of providing accurate, complete, and detailed information- can ensure that interviewees are candid during their interviews. In addition, preparing the client upfront for the possibility that the report will not be helpful, and clearly explaining that the expert is independent, can minimize anger and disappointment later.
If the expert has not conducted a comprehensive review of relevant materials, he/she may be subject to harmful cross-examination. The expert’s failure to review such materials can also be grounds for reversal."