So... I think we're almost at the end of this story. Probably 2 or 3 more chapters to go.
Review~ :)

L gave the boys the next day a day off. After their classmates sudden death every class was halted for the day anyway. The funeral would be held later that day. Because Raoul was an orphan, just like the rest, there weren't many to say their goodbyes to the boy and so he would be buried faster as normal.
He took his eyes of the laptop screen he sat crouched in front of and permitted himself to take a quick break.

I'm almost 100% sure now the murders are done with the Death Note. I can't think of another way to succeed in that many and strange murders and suicides all over the world.

He sighed and nibbled on the flesh of his thumb. There must be something… something that could help him and solve this case. His thoughts slowly drifted off to past memories of his interrogation with Light Yagami. The last time he saw Light before he died.

~~Flashback~~

'We found two notebooks in the apartment of B, just like you said,' L said. He shuffled into the small interrogation room where Light sat by a table. L crouched down on a seat on the other side in front of the killer. 'You told me earlier that these are "Death Notes" and are the weapon you used with B to kill. I've already seen the rules in one of the Death Note and the names in both of them…'

Light flinched every time L dropped the name "B", but that didn't bother the detective. Maybe they really were more than partners in crime… friends maybe? It didn't matter anymore.

Light raised an eyebrow. 'So? What more do you need to ask me? The rules are clear enough, aren't they? Write a person's name and picture their face. That's all what's needed for them to die of an heart attack.'

'And the few criminals that wrote with their own blood on the wall before dying?' he questioned. 'That was the Death Notes doing as well?'

'Yes,' Light confirmed. There was no use in being difficult for him now. 'You can let someone do something and control the way they die too… but it isn't possible if the task is impossible to complete. Then they will die of an heart attack regardless.'

L nodded slowly. 'Alright, then I think all what I needed to know is answered. I'll need to destroy the notebooks as soon as possible. No one should be able to use such a terrible weapon of destruction.'

Light huffed and turned his head away from the detective. 'It was a perfect way to destroy the criminality in this rotten world,' he muttered.

L stood up from his chair and stared at the young man. 'Your way of "cleaning" this world sounds like a childless dream. There'll always be criminals in this world. The dark can't exist without the light and the light can't exist without the dark. It's called balance of good and evil.'

Light stayed silent and didn't look L into the eye.

Just when L was about to leave the room he turned around again. 'There's one last question I like you to ask.' He paused. 'Has the Death Note the power to pull someone to the dark side? To manipulate the owner's thoughts?'

Finally Light looked up again and turned to him. Both stared at each other for a long time before Light answered.

'The Death Note does not have such powers… It depends on his owners willpower and character how it will be used. That's my theory.'

~~End Flashback~~

'It depends on the owner's willpower and character how the power of the Death Note will be used,' L softly said to himself.

Roger had a heart attack, strange murders and suicides all over the world, criminals started dying of heart attacks again, the boy Raoul who had a sudden accident the day before… there was something that connected most of these…

Mello.

Mello got punished by Roger and right after that he got an heart attack. Mello has a sense of justice as well since he wants to succeed him to be the greatest detective of the world. Mello was also the one who got into a fight the day before Raoul's death.

It doesn't explain the strange murders and suicides all over the world, but it's enough to suspect him highly. L's eyes widened when something occurred to him. Mello was the one to find the first and only clue we found so far with The Mystery Murders Case.

He quickly began to type many passwords into his laptop that would give him access to the footage of the camera's in the hallways of Wammy House. It wasn't something he did very often, but it was necessary now.

He watched Mello and Matt walking together for most of the time. They are almost always together… does Matt know something as well? It was the morning of Raoul's death and when Mello went into the canteen he saw a surprised expression appear on his face before it quickly disappeared again. Why is Mello surprised to see Raoul when he would die that day at noon? Was he supposed to die earlier? L went quickly through the hours of the morning and stopped the footage at the moment Raoul fell off the stairs. Mello didn't look as surprised as a normal person would be if their classmate would fall off the stairs. There was some surprise and shock on his face, but it looked fake. As if it was a mask he pulled over his face to hide his true emotions.

L paused the footage and stared at the screen for a moment. Calculating his next step. He didn't like this at all… but it seemed that Mello was in possession of a Death Note and was killing with it.