@burcinc-- Actually, things don't really work the way they are shown in TV shows. Many of those shows present such advanced technology that doesn't really exist or is in use. I guess they have to do that to make things more interesting on screen.
The work of a forensic toxicologist is interesting but it's also difficult and high pressure. Like the article said, compounds aren't easy found in the body because they change form as they are metabolized. A forensic toxicologist has to be very knowledgeable about all the various forms of compounds and where to look for them. It's true that their findings can take an investigation in a whole new direction. So it's a high stress job with a lot of responsibility.