A friend of mine recently mentioned on his blog that one of his top career choices is forensic science. This struck a nerve for me so I began to leave him the following comment, but decided it was better said in its own post.
As for forensic science: do you mean to be a pure evidence investigator or (as I assume) do you mean to be a coroner/medical examiner? When I was younger, I was very interested in doing the latter. (At least your patients don't complain!) But then I encountered two things. First, you have to be really really good at hard science (virtually a chemist, pathologist, histologist and physicist in one), which sadly isn't my bag.
Second, and more important, you have to deal with some really really awful homicides, suicides and general gore. I cannot recommend strongly enough that you go to the library and look through an ME casebook (with lots of photos), and then see how you fare. Seven years ago for me (in Chicago), a mere twenty minutes flipping through such a book cured me pretty much forever of wanting to be a coroner. There was in fact a single photo (rape-mutilation-homicide) that closed the career for me. I still shudder to think of such brutality.
With my interest in (emergency) medicine, I have no problem with blood and trauma and patient pain. But what I knew I could not endure was immersing myself in the brutal world of death death death. Obviously, it's a dirty job and someone's got to do it. The question is, though, "Are you 'someone'?" I am not. I have a strong stomach; I just don’t have *that* kind of strong stomach.