Tuesday, July 19, 2011
I was reading the comments by readers of the story that appeared in the NY Times on July 18, 2011 regarding the chloroform searches in the Casey Anthony case.
Software Designer Reports Error in Anthony Trial
Several people commented that they didn't understand why John Bradley didn't notify the defense team or the media of the discrepancy in the 84 searches for chloroform in the Casey Anthony case.
First of all, the defense team was notified of the discrepancy by me as I was in Orlando during the trial and gave Jose Baez the questions to use to clear it up once it came out in testimony.
However, there is a valid reason why John Bradley did not notify the defense team or the media: That would be against the rules.
What happens in cases involving experts is that the expert has an ethical obligation to notify the attorney he is working for of any mistakes or errors that he or she notes in the evidence so that the correct facts can be presented to a jury. What the attorney does with that information is not up to the expert.
Also, experts on opposing sides of a case cannot discuss the case in any way as that would also be unethical.
I have also received numerous questions about why I didn't testify in rebuttal since I was working for the defense team. Mostly from fellow experts in other countries that have rules different from the US legal system.
In the US, in order for an expert to testify, they must be disclosed to the other side prior to testimony, and are put on the witness list. I was originally on the witness list, but was taken off so that I could assist in other areas of digital forensics as a consulting expert. Since I was not disclosed to the other side as an expert any longer, I could not testify at trial.
The defense team had a testifying expert on the witness list, but he withdrew from the case prior to trial. So by the time trial started, the defense team did not have any testifying witnesses for the computer forensics. Everything that had to be done regarding the computer forensics testimony at that point had to be done via cross examination or during rebuttal testimony, which is much less powerful than having an expert testify.
While there was an error in the results of the analysis by Cacheback, it is the responsibility of the computer forensics experts to verify the results and check the reports of any expert on a case.
There have also been reports that both programs' analysis contained errors. However, the difference was in how substantial the errors were. Based on my analysis of the evidence, the NetAnalysis errors were not substantial and had no impact on the results from an evidence standpoint. The CacheBack error was substantial in that it presented evidence that would have substantial impact on the understanding of the jury as to the facts in the case.
The expert's job is to assist the triers of fact in understanding the evidence. That means that the expert has to make sure that the triers of fact hear evidence that is accurate, independent of the impact on the case.