Document examination expert witness Ronald N. Morris is a certified forensic document examiner and in this excerpt from Submitting a Handwriting Case for Examination, he writes some final thoughts.
A very important point to remember, all of the submitted collected or nonrequest and known writing used in the examination and comparison process must be admitted as evidence in court at the time of trial. All conclusions in the results of the examination section of the report are based on the examination and comparison of the submitted questioned and all of the known writings. Any change in the number, status, or admissibility of any of the writing submitted for examination and comparison, including the exclusion of examined writing at the time of trial, will impact upon the conclusions as stated in the report. In this case, the conclusions in the report are no longer valid and a new examination and comparison will have to be conducted using only the writing that will be admitted into evidence. The reason, the conclusion reached by the examination and comparison process is based on the combined significance of the evidence in the examined writing. The same is true if additional writing is added at the time of trial.
All examinations and comparisons must be conducted in an appropriate setting, using recognized and acceptable techniques, and examination aids as necessary. While testifying as a witness in court, during a deposition, or any other judicial situation absolutely NO examinations and comparisons will be performed. NO new opinions will be given, on or off the record, until a comprehensive examination and comparison of the evidence has been done. The only opinions given as part of the expert testimony in court or at a deposition will be those based on acceptable examination and comparison procedures and reported in either a verbal or written report.