Got the time is a flat circle clock, here (it is squashed so I can't read it, but that is OK, because time stops when I watch True Detective).
I don't usually get HBO except for free promos, don't watch most of their own series (caught season one of True Detective after the fact on Netflix, but have since dropped DVD plan, and have streaming only), and movies are in such heavy rotation. I still have a bunch of movies taped from the three free months when I rejoined a year ago. I do sometimes add it for a month (have to sign up for three months, $12.95 rate, but can cancel after 30 days) around this time of year for Hard Knocks, which I did today. So between free On Demand, and running previous episodes from now until (mostly) Sunday, I can be caught up by the finale.
*SPOILERS?*
Noted in one of the recaps, there is a crow picture above Pitlor (Rick Springfield, shrink and plastic surgeon) in a shot from his office. Also, the use of acid on the eyes of two of the vics (Caspere and Stan) was characterized as being done with surgical precision, the kind he might have, as the only character with a medical connection.
Also from a Polygon recap, Ray's father (Fred "Remo Williams" Ward) as ex-LE could be significant, as Ray was shot by a riot gun right after discovering Caspere's hard drive - the kind of non-lethal ammo a cop or ex-cop might have. His old police boss would also fit this description, as well as the one from the since murdered Mexican hooker, about a thin, pasty guy. A good point brought up, why wouldn't the murderer of Caspere already have taken the hard drive in the first place? Maybe the murderer/s of Caspere (if they are the child siblings from the blue diamonds heist/caper, possibly Chessani's adopted children?) are different, and have different motives from those looking for the hard drive/orgy blackmail material? Though Chessani's son would seem to overlap and be in the second set of motive as well, if Pitlor is a reliable witness (the blackmail scheme cooked up by Caspere, Pitlor and Chessani's son, at least), so that might not fit as an explanation.
Another theory was that Osip (Russian gangster, betrayed and double crossed his supposed partner VV in the rail land deal) was in a short list of people that checked off both suspect boxes - those that could have known about the blackmail scheme (most of the orgy bait were Russian) AND been able to leverage and benefit from it.