All of his activities on that day are relevant to creating a complete picture of what occurred, and journalists choosing to withhold details and information is kind of a slippery slope?
EDIT, including this here so it is higher up in this argument thread:
Police will disclose and journalists will often report the number of weapons and ammo or any explosive devices found at the perpetrator’s home, even if they were not brought to the scene or used in the crime. I think the ladder is a detail in the same vein because it is equipment that he had available to him.