I don't believe anybody here can really accurately state he is innocent or guilty. Let the evidence come out and then we can form an "opinion".
I will say, we know Alec lied, video contradicts his statements. Bad decision to lie. Never lie as it will come back to haunt you.
As for some saying something about an "affair" or something like that and having nothing to do with manslaughter. I watch the ID channel, I apologize in advance , there are many murders when "affairs" are involved. Although I know NOTHING about it in this situation, just saying.