CNN is reporting that “[i]nvestigators are struggling to build a federal murder case regarding fallen US Capitol Police officer Brian Sicknick” and they’re “vexed by a lack of evidence that could prove someone caused his death as he defended the Capitol during last month’s insurrection”:

Well, yes, “who killed him?” is an important question. But so is, “how did he die?” Because that information hasn’t been relesed:

So far, they can’t identify “a moment in which he suffered his fatal injuries”:

And “[m]edical examiners did not find signs that the officer sustained any blunt force trauma, so investigators believe that early reports that he was fatally struck by a fire extinguisher are not true”:

An excerpt:

So, what else don’t we know yet?