Should I add more or is this sufficient?
Leaning closer to see the presentation Mr. Lee had displayed on the TV, I was completely enveloped by the concept that this National Geographic's video explained. The idea that my ancestor's footsteps could be traced through something as small as mitochondrial DNA was amazing. There was a whole different part of this world, just below the surface, where pure explanation thrived. I had found my niche; science was both my fascination and my motivation.
With the passing of each school year, I found new aspects of science to love; anatomy and physiology of the body, chemistry behind reactions, biology of plants, and physics of movement. But when I discovered law, I was caught in a love triangle. I needed to find a way to combine both of these passions into one career, and the solution that I found was criminology. Science always came easily to me, while law was a welcomed challenge. The thought of being able to influence the justice system through science is a dream to me. With the ability to major in forensic science, I will be able to help others while satisfying my appetite for problem solving, science, and law.
A love triangle normally involves three things (hence "triangle"). You list two: science and law. This could be a problem. You might also want to focus in more detail on which sciences you like best, how they connect to law via criminology, that sort of thing.