Jeremy Downs is a character in DEXTER. He was a 19-year-old living in a halfway house after he is released from juvenile hall. At the age of fifteen, he was convicted for killing another boy. Though the police assumed it was a sloppy crime of passion, Dexter saw the work of someone who had studied and prepared to be as brutal as possible by cutting several major arteries ensuring a bloody death.
Plot
Season One
Dexter follows Jeremy and a boy named Lucas into the swamps where Jeremy claims he is going to show his friend an alligator while secretly reaching for a knife. Dexter interrupts the boys, who both panic and flee. When Dexter returns to his car, he finds the window smashed and his wallet missing. Later that night he attacks Jeremy alone in the halfway house. Before he can be rendered unconscious though, Jeremy threatens to kill Dexter like "the last guy" who raped him, implying his first murder was actually self-defense. When Dexter asks why he never told the police about it, Jeremy implies he was too ashamed. Dexter quickly changes his own story to being that he followed Jeremy just to get his wallet back. Before leaving, Dexter warns him that while his first victim may have deserved to die, the boy Jeremy almost attacked in the swamp didn't, and encourages him to only kill those who deserve to die.
Days later, another body is found matching the wounds of Jeremy's first victim, leading Dexter to believe Jeremy had not taken his advice. When he attempts to track Jeremy down, he discovers he sells sexual favors to random men in a nearby park, which convinces Dexter he was lying about the rape attempt as well. Dexter goes to the park and attempts to confront Jeremy again, but Sergeant James Doakes arrives and arrests Jeremy instead. While he is detained, Dexter talks to Jeremy who revealed to Dexter that he kills because he is trying desperately to feel something and feels "empty" all the time just like Dexter. Dexter is sympathetic to Jeremy after this and feels he may have a connection to him. He later visits Jeremy in prison, feeling he is the only one who can understand him, and vice-versa, but finds Jeremy had taken his advice and killed someone who, in his own mind, deserved to die: himself.