There's actually a name for this. It's called the "CSI effect," so called after the famous and numerous "Crime Scene Investigation" shows, or "CSI" shows on television.
There are numerous ways jurors perception of proceeding may be distorted. First, many expect there to be much more forensic evidence that usually is available. Secondly, and in conjunction with the first, a lower value is often subscribed to circumstantial evidence. A third general expectation that frequently distorts perception is that technology is more advanced that it is. Finally, the levels of expertise in evaluating evidence is often inflated.