by: Steve Linn
You may have heard the tragic story of Glenn Ford.
Thirty years ago Ford was convicted of a murder he did not commit. He served thirty years on death row before being exonerated of the crime.
Two of the prosecutor’s star witnesses were “expert” witnesses. One was the coroner who later admitted that he never even examined the body!
The other was a police officer who identified himself as a fingerprint expert – but had no credentials.
Humans are hard wired to believe testimony when it comes from a person with credentials.
Juries often simply accept expert testimony as gospel.
But what if a prosecutor’s witness is not qualified? Or worse, what if the expert is only
giving the jury half of the story?
Indeed, incriminating testimony from a so-called expert can be very compelling and put your client in a very vulnerable position.
In fact, I worked on a case where a man was at risk of being accused of possession of child
pornography. The State’s computer forensic expert insisted that he had downloaded and
possessed criminal material.
However, this just was not true. The client’s computer had been infected by a third-party
software called “Frost” which moved the subject content onto his computer without his request or
In other words, it was the digital equivalent of somebody coming into your home and hiding a murder
weapon in your attic.
A scenario like this one is very technical and expert testimony of this nature is likely to go
far beyond the knowledge a jury member has about computers and technology.
In consequence, without meaningful cross-examination, a jury may be forced to simply
accept such expert testimony at face value.
Indeed, it is a scary scenario to imagine!
How do you conduct meaningful cross-examination?
You get prepared. You learn about the tools and ways that an expert analyzed the data.
Was his process flawed some how? Did he or she use reliable tools to come to the conclusion?
What are some alternate explanations for the conclusions that the expert drew from the investigation?
These are all critical questions you can ask yourself.
Otherwise, your client risks being held hostage to their analysis.
This is where we can help you. If you are handling a similar scenario with digital forensics, you owe it to your
client to seek an alternative expert opinion so that you can dig into the information and get the big picture.