"Amp" is one of the Goldens at the Graveyard, given the nickname because he is loud and is often the one to address the crowd of Unwinds through a megaphone.
He and the other Goldens were all murdered, left to suffocate and die in a crate, by the clapper group at the Graveyard: Mai, Blaine, and Cleaver. Amp was said to have his eyes wide open, staring at nothing, which is how Connor came to realize that they were all dead, and not sleeping.