I think four people might have wanted her gone that night,Bido gave it a shot, but couldn't pull it off, so it wasn't her.
That leaves blondie, ML, or maybe even the girl's mom she could've totally sent someone to do it. The mom did say he needed to get over it and let her go.
But Blondie will do anything for Bido.
So, ML finding the machine *could* suggest it wasn't him, but that doesn't necessarily mean he didn't kill her *that* night before Blondie or someone else got to her.
So, he got rid of the evidence on the floor, right?
Here's what i think:
1. He wiped it away because he's the one who did it.
2. He cleaned it up because he was actually thinking about killing her himself but couldn't go through with it. So, when someone else did it, he was kinda relieved and got rid of the evidence.
3/He cleaned it because he figured it was Bido and he didn't want her to get in trouble like he did when he was her age.
From what I've seen it in the next chapter, it could be that he always wanted to kill her but he didnt bring himself to do it for some reason. And u might be right that the blonde could do it, because the fl couldnt bring herself to do it either but she wanted to. But how can it be the blondie when the time she wanted to kill her. And the night Bido went to sleep, there's a possibility blonde did it the same night until the next day the ML found out
Shit was so good, but I cant tell whether the FL killed the wife the night before or he did