What is the climax of the story "The Tell-Tale Heart"?

I agree that the climax to "The Tell-Tale Heart" comes at the very end when the planks are torn up to expose the still "beating heart." It could be argued that the climax occurs earlier, when the narrator finally kills the old man after so many days and nights of patient waiting. Certainly, there is a suspenseful build-up to this action. But because the story continues to build even after the murder, and an even more surprising and terrifying event occurs, I find the true climax at the end when the body is exposed to the police.