FRE Rule 26 asks, where are your notes?

Remember your math teacher demanding that you "show your work." Forensic science is no different. We want to see your process, your thoughts, your notes ...

"The law, however, expects expert witnesses to write reports for the court, outlining their opinions on the matters about which they are testifying. In the eyes of the law, the expert's testimony is allowed by the court only to the extent that the expert adequately documents the basis for it in a report and makes it available to the opposing party before the trial." - from A Guide to Forensic Testimony: The Art and Practice of Presenting Testimony As An Expert Technical Witness (link).

The key to understanding how the legal process requires you to document your opinions lies in FRE Rule 26.

(2) Disclosure of Expert Testimony.
In addition to the disclosures required by paragraph (1), a party shall disclose to other parties the identity of any person who may be used at trial to present evidence under Rules 702, 703, or 705 of the Federal Rules of Evidence.

Except as otherwise stipulated or directed by the court, this disclosure shall, with respect to a witness who is retained or specially employed to provide expert testimony in the case or whose duties as an employee of the party regularly involve giving expert testimony, be accompanied by a written report prepared and signed by the witness. The report shall contain a complete statement of all opinions to be expressed and the basis and reasons therefore; the data or other information considered by the witness in forming the opinions; any exhibits to be used as a summary of or support for the opinions; the qualifications of the witness, including a list of all publications authored by the witness within the preceding ten years; the compensation to be paid for the study and testimony; and a listing of any other cases in which the witness has testified as an expert at trial or by deposition within the preceding four years.

These disclosures shall be made at the times and in the sequence directed by the court. In the absence of other directions from the court or stipulation by the parties, the disclosures shall be made at least 90 days before the trial date or the date the case is to be ready for trial or, if the evidence is intended solely to contradict or rebut evidence on the same subject matter identified by another party under paragraph (2)(B), within 30 days after the disclosure made by the other party. The parties shall supplement these disclosures when required under subdivision (e)(1).

You see the emphasis made on turning over everything in discovery. Notes, reports, and your complete CV. In the world of e-discovery ... this also means notes and reports generated by the programs that we use - if any are created.This means the History Log, in Photoshop or Amped FIVE, is more than likely discoverable. It's a record of the steps the software has taken (at your direction) on an image or series of images, video, or ...

Bottom line, take good notes. If you'd like to know more about taking good notes, standards compliance, and other foundational aspects of forensic video analysis, check out our on-line course Introduction to Forensic Multimedia Analysis.