Hi,
I just wanted to weigh in on this case as a verified mental health professional. Before I even learned that EL was previously diagnosed with Bipolar II, I had already come to the conclusion that she appeared to be suffering from a psychotic episode. The video of her in the elevator shaft shows her engaging in behavior that I immediately recognized as typical of psychosis (my primary job at this time is working with people with schizophrenia, Bipolar disorder, and other disorders which feature periods of psychosis).
EL appeared to be responding to internal stimuli (i.e. voices, command hallucinations telling her to do certain things) as well as possible visual hallucinations. The repetitive, disorganized, and agitated nature of her actions is indicative of a psychotic state -- I have seen this exact, same behavior time and again in my clients when they are suffering from psychosis.
It is possible EL was suffering from a psychotic break as a result of her Bipolar II diagnosis. It is also possible she had been misdiagnosed and a more proper fit would be Bipolar I, schizophrenia, or some other diagnosis. The fact that she was 21 years old also makes me question this, as symptoms of schizophrenia are often not apparent in women until they are in their early- to mid-20s, when they have their first true psychotic break (men tend to suffer a first psychotic break at a slightly earlier age, around 18 or so). So, I would be curious to know when she was diagnosed with Bipolar II and how she was being followed and treated, medically and psychiatrically.
So far as theories go, I find it infinitely more plausible that, in a psychotic and paranoid state, EL died as a result of misadventure than the theory that someone drugged and murdered her, dragged her dead-weight body not only to the roof of the hotel but ALSO to the top of the water tank, and then hoisted her in.
I believe EL, suffering from paranoid psychosis, made her way up onto the roof of the hotel (to hide from imaginary threats), disrobed (as a result of command hallucinations), climbed the red fixed ladder on the side of the storage room, jumped down onto the top of the water tank, and, trying to find a place to hide from her imaginary threats, climbed into the water tank, where she subsequently died.
The notion of a murderer preying on someone in a psychotic state and disposing of her body in the manner he supposedly did is ludicrous to me. There is a video showing a 6', 200lb man struggling to carry a 90lb dummy (that's 35lbs less that EL weighed) up a ladder. How on earth did someone carry a 125lb EL up the ladder? And why would they do it in the first place? If you killed someone, whether premeditated or not, that seems like a) a lot of trouble to go through to dispose of the body and b) extremely risky, considering it would take a lot of time to complete the task and it would be highly visible to others. Why not just leave the body somewhere more convenient?
In essence, I 100% believe EL died as a result of misadventure due to paranoid psychosis resulting from mental illness. It is so sad. I wish she had received more adequate treatment and monitoring.