I Think, He Kills

Jaron Barsum is not normal. He may never be, Clincally diagnosed with psychopathy, schizophrenia, and OCD, Jaron is shunned away from the rest of the world. What only a select few know that Jaron is one of the smartest teenagers in the city. Give him a problem, he can analyze thousands of possibilities, narrow it down, and give you a perfect plan in under fifteen seconds. The police even ask for his advice, though his parents don't know it. Jaron knows that he can't feel emotion, but when his mentor at school, who is the tight-end for the high school football team, happens to have his cousin Emma for the year, Jaron experiences something he doesn't know what to do with. After a while, Emily and him start actually having a relationship. Jaron finally feels calm and finally starts relaxing.
Then the murders happen.
When three bodies turn up around the city, each with a red x inscribed with each body, the city grows nervous. The police don't want Jaron to take the case, since he is a minor. But when Jaron finds that all these murders are connected to him, and that the killer is targeting him, he takes on the case by himself.
But what he discovers will shatter his whole world and will force him to decide to do something that his whole life he fought against.