The AP just sent out a bulletin, but there's not much information online as of yet. There's live video on the Denver CBS affiliate's website, which is claiming that there are "possibly two victims." We'll update as necessary.

Tomorrow is the first anniversary of the Sandy Hook shooting.

UPDATE 12:50 PM: The sheriff should be making a statement soon. For now, the AP says:

UPDATE 12:54 PM: Arapahoe County Sheriff Grayson Robinson says that a man entered the high school carrying a shotgun, looking for a specific teacher. One student was shot and is currently in critical condition, another student was found with what appeared to be "a minor gunshot wound," although Robinson says they're not entirely sure it's a gunshot wound. He says that the suspect is deceased and appears to have shot himself. Robinson didn't name the suspect, but he confirmed that the suspect was a student at the high school.