I am surprised to find that many private investigators do not bother to review all of the discovery on complex cases, such as those that we encounter in criminal defense work. When I take on a new case, I ask the attorney for all of the discovery, so I can review it before conducting any field work.
Just by simply reviewing discovery, I have found information that has helped my attorney-clients win in trial or get cases dismissed. One recent example comes to mind. It was a shooting incident involving two vehicles. My attorney’s client had been charged as the shooter. Surveillance video provided in the discovery showed my attorney's client getting into one of the vehicles on the rear passenger side. It then showed the vehicle departing just prior to the shooting incident. Later, I reviewed Axon bodycam video from an officer who was interviewing the gunshot victim. During the victim's statement, he said that the shooter had come from the front driver's side of the vehicle. I was surprised to find this, because the officer had omitted that information in his narrative of the interview. This simple find helped the attorney to get a not-guilty verdict.
Another recent example was also a shooting incident in which my attorney’s client had been charged as the shooter. The shooting occurred in a residential neighborhood, and the initial 911 calls were provided in discovery. In the calls, a neighbor said he saw the incident and knew whom the shooter was. Furthermore, he knew this individual by name. And the individual he named was not my attorney's client! I interviewed the witness and confirmed the information. The information allowed the attorney to get the case dismissed.
I find that attorneys are often overwhelmed with their caseload and an investigator can serve as a second set of eyes. The attorney may not have the time needed to sift through large amounts of discovery and therefore, it is a good role for their investigator.
I think a good investigator also has a methodology for organizing the sometimes overwhelming amount of information provided in discovery. I use structured analysis techniques to do this. Understanding and organizing the information in discovery becomes crucial when interviewing witnesses and conducting other fieldwork. And sometimes, there is information buried within discovery that completely changes the case!