This might be rediculous and far fetched, but I think he either murdered this girl because he lost his mind or he watched someone else murder her, and the song is all about him remembering everything they did together while he's being interrogated in some institution. "Do you remember when you saw her last?" Would be the police/psychiatrist and all he can respond is "Her skin is cinnamon" because he's lost it entirely.
This might be rediculous and far fetched, but I think he either murdered this girl because he lost his mind or he watched someone else murder her, and the song is all about him remembering everything they did together while he's being interrogated in some institution. "Do you remember when you saw her last?" Would be the police/psychiatrist and all he can respond is "Her skin is cinnamon" because he's lost it entirely.