Me at the start of college: I want to be a history teacher.
Me at the start of med school: I want to do internal medicine, perhaps an ID fellowship.
Me currently: I like path.
Don't count your chickens yet. You may discover that 1) you really like another branch of medicine, or 2) you find yourself actually not that interested in forensics. I think interviewers like to see that you have thought about your potential future career, but that you have also thought about the fact that you will be in med school for 4 years, being exposed to so many different branches of medicine, and are open to trying new things and exploring other potential pathways. You have already indicated that you have changed your mind previously in regards to possible Phds, etc. I agree with Mr. Fremitus as well.
If you maintain a focus on forensics, you may be asked why you want to go to med school, and spend 4 years studying many things that you may not feel to be important. Why not become a cop and investigate crime scenes? Why not be an autopsy tech and do most of the work? Why not get a PHD and learn toxicology or ballistics?
That being said, med schools do not usually look for a certain type of student in regards to career choice. What is more important are characteristics such as intelligence, eagerness to learn and explore your own boundaries, working well under pressure, being a team player and working well with others, and people who understand the benefits and drawbacks of medicine as a career.
p.s. Don't underestimate the power of the personal statement! On most of my path interviews (particularly the ones where the interviewer actually read my file!) I received comments about it, such as "I appreciated your thoughts," or, "I really like what you said..." Serves as a jumping off point for conversations, as well as giving them a way to remember you after you have finished the interview.