In episode 5, last week, our attention was brought to bear on the guy who did not come forth to police when his friend did, after the two encountered Naz and Andrea right outside her apartment. In fact, Trevor went out of his way not to mention his friend, when he gave his otherwise truthful (as far as know) account to the police. I guess Trevor himself can be considered a suspect, but his friend certainly seems more suspicious.
Then there's the guy who offered Andrea a ride in his hearse. He either could be someone hired to track her and kill her, or someone who took a sick, lethal liking to her, and followed through.
And if we're talking about someone hiring Andrea's killer, we now have Don Taylor, and a nice big financial motive. He also doesn't seem to be a very nice guy, for whatever that's worth.
So where does that leave us? The killer could still be Naz, a possibility the story is keeping at least slightly in play by revealing his past propensity for violence (and which we've seen again in prison), but I still don't think so. I thought from the beginning that maybe Naz's brother was somehow the killer, but we've seen nothing in that direction at all, so far. And the killer could still be someone we haven't met as yet - but it's getting pretty late for that.
So I would say there's a better than 50/50% chance it's one of three main suspects, but I wouldn't put money on any one of them, and not overwhelming odds on it even being one of three. I would add that there's no way Andrea committed suicide, and since this is not science fiction, it can't be the cat.
But the cat has some connection to this, and, at very least, it's good to see Jack taking care of the cat, and his foot condition finally cured!