It was the one thing at the scene that didn’t fit with the crime. There were no cult aspects, no wax for torture. Hell, it wasn’t even needed as a light source. So why did every scene have a big white candle? The reason for the candles might hold the clue to the killer.
Why burn candles? Not light, not cult ritual. Wait? Ritual. That’s it!
“Hey, Carl. Weren’t the previous victims named Mary?”
“Son of a bitch! This guy is Catholic. He’s killing virgins and lighting prayer candles for them to the Virgin Mary. Sick, twisted bastard.”