Yea even just a vague cause of death would be revealing, I honestly think LE kinda bungled their public outreach efforts by being so closed lipped, I understand the importance of discretion; but if we don't know anything other than this may or may not be the guy who may or may of not did this or that, the public really isn't going to be of much use.
The hinted at some the crime being about "power" but literally every malicious crime is about power when you get down to the nitty gritty. Burglaries are largely about power and violating people, robberies, stabbings, fights. If the crime was sexual I assume there wasn't activity that would leave dna, but would still satiate that compulsion.
Also by them being tight lipped it makes it sound like to me that they have literally nothing but a bunch of educated guesses, which could work in their favor if they are surveiling someone; but if they don't have a suspect identified they are just hindering the investigation.
If you don't have anything, you do everything you can to get it within procedure and the law. I have never seen a case like this honestly, I understand the respecting of victims aspect too, but I say respect their memory by not letting the case go even colder. William Butler Yeats said, don't wait till the iron is hot to strike; make the iron hot by striking. Forensics, this and that don't make up for good old fashioned police work imo.