Or was it possibly a Becket situation, with the retainers acting on their own to remove an obstacle to Æthelred's accession to the throne, knowing this was what their mistress wanted?
Whatever the case, the murder of a king was shocking. Kings were considered to hold their position by divine right, and killing one was an egregious sin. The hasty burial at Wareham was "unceremonious," to say the least. A year later, the body was removed to Shaftesbury Abbey. When they dug him up, he was deemed "uncorrupted," a sign of saintliness.
Contemporary chroniclers telling the tale of the murder do not name the murderer(s), which is unusual since they would be known, and presumably punished. This reticence could be explained by the writers avoiding naming publicly the person they deemed the real culprit, Ælfthryth. Naming the woman who had been crowned a queen as a plotter of assassination
Chroniclers could also have avoided naming the murderer(s) because they were retainers of Æthelred, and since he was by default the next king, any suggestion that he might have instigated or planned the murder was a chancy idea to put into writing.
In any case, the young Æthelred became king. I've written about him several times, so I want to fulfill a promise I made two days ago, when I said here that I would have more to say on Edgar's "middle" family, his second consort and her daughter. See you tomorrow for the story of Saint Edith.