Quote from Tatsu;183135:
Also, people aren't allowed to randomly kill people for fun?
He was being blackmailed by the student. Marital issues. She didn't die directly, but he hit her and he thought she died, so he locked her up in the basement.
She woke up, but she was locked inside, and she died slowly.
He heard that the building was going to be demolished soon, so he went back to dispose of the corpse, but accidentally ran into the students. They didn't notice him, but he was caught in a picture from one of the student's cameras. The student lost the camera in the building, but the teacher already revealed too much and ended up killing him too.
He doesn't reject the money because the hospitalized girl's father handed it to him, but because he's says its even since the girl's ghost sister saved him (and she did multiple times). He's showing a tsundere side.
They become friends when she asks him if she can talk to her sister though him again in the future.
The suspiciously shoddy case I mentioned with the fox ghost, doesn't even exist in the manga. Its a filler, and a terrible one at that, which contradicted the first episode.
In any case, the manga is worth reading. It undos all the criticisms I mentioned above about the anime. Yakumo is a tsun tsun, and the girl is a straight-man type character. The crimes aren't solved with plot devices like "finger prints", events don't contradict each other, and since the series is done in a first person view of the heroine you have a much better understanding of whats going on in the character's minds.
Seriously, this is one of the worst anime transitions I've seen ever. I already felt there was something odd about the series from the very start, when Yakumo suddenly points out that Haruka had a dead sister and she just accepted it so fast. And then I knew there was definitely some sort of problem when the "detective" showed up and started helping out with forensics. Such an easy plot device.
The anime industry seriously can't be complaining about piracy when their quality is always dropping. I haven't watched a single good anime since mid 2009.