How does Kira kill?

A question that has plagued L's mind ever since the case got his attention, and regardless of the countless hours he's spent doing research, he couldn't confidently tell just what exactly the method is.

Simultaneous heart attacks on a particular social category; it has been already proven that this is no coincidence.

However, it is humanly impossible to commit the act of murder without direct use or exposure to any known sensory channels or physical interaction, but there is no doubt that Kira needed both a name and a face to kill, as nothing happened to criminals whose names and faces were intentionally not published on television to test Kira's abilities, therefore the possibility of Kira being just another human being is quite likely to be the case.

Is there a way for humans to kill other humans through hidden interactions within thin air? That would be highly unlikely, but then again, scientists have proven that interaction between human beings through satellites and electric waves creating what is now known as Internet is indeed possible. However, that would be interaction alone, and not actual control of the human physique. To be able to control, modify and deactivate the functions of a human's organs by another human from a distance is not yet possible. The only possible way is for that human to get scared to death, which does not fit this case as none of the victims has been shown to something remarkably abnormal or has displayed any unusual behavior before their death.

Is this the power of telepathy? There is yet no evidence proving the existence of such power, and even on the off chance that it does indeed exist, and this was the case, telepathy deals with an exchange or transmission of data from one mind to another, also called "thought transference", and not direct control or possibly possession of the human organs' functions. The only explanation that could be considered as valid is for the killer to transmit commands of modifying or canceling some of the bodily functions to the victim's mind, therefore having absolute control of the brain cells which are responsible for each and every bodily function. If this were the case, the killer would have chosen to switch off the part of the central nervous system which is responsible for the heart. By stopping the synapses from doing their natural function, which is assuring the communication of brain cells and the transmission of signals between neurons, it is quite likely that the heart would stop working because the brain cells would be damaged by then.

Or..

A drug that has been injected into the body allowing it to shut down the synapses responsible for the function of the heart is another possibility. However, this is highly unlikely seeing that many victims were monitored before their death and did not inject into their bodies anything of strange nature. Additionally, the cause of death is merely a natural heart attack, which means it would be quite difficult for any drug to cause such thing so successfully and with no risk of failure whatsoever.

This is completely absurd.

Telepathy does not exist and even if it does, the mere thought of being able to possess the brain of another human from a distance is equally ridiculous.

L was a man of science and he based all his theories on cold facts or alternatives that could possibly happen based on these facts. He was an atheist and he didn't believe in the supernatural because his brain simply did not accept the existence of things that might go beyond it or didn't offer any route for it to know about them, therefore this case has been a challenge to both his sanity and his mental state.

He tried not to get too frustrated for starting to doubt his convictions because in reality, these were not true convictions to him and were rather conclusions he had drawn in his developed mind for so long.

The supernatural.

Was this the real cause of the deaths? If so, L and no one had the power to face such thing. But the fact that the killer needs both a name and a face is enough proof that even this phenomenal power has its limits, therefore even if the supernatural does indeed belong in the equation, it does only partially. A possible assumption is a human possessing supernatural powers, which would stop them from going completely divine. But, to kill someone by a heart attack? This seems like it would only happen by wishing this upon the person, or else there wouldn't be any other way for it to happen.

"Kira never stopped killing while the surveillance cameras were in place. I still have no idea how he's been able to commit these murders but, let's say he could kill someone simply by wishing death upon them. You'd think that any human being would have shown at least some emotion, some sign that they were knowingly committing an act of murder, so the obvious conclusion is that Kira couldn't be one of them [the monitored suspects]. However, what if he is one of these people we've been watching? If he is, we have to assume that his psych has reached god-like proportions; punishing evil doers without the slightest change of expression, it almost makes me want to believe that Kira doesn't exist, that this is just the wrath of a revengeful god. But that idea is completely absurd; to think that god would need a person's face and name to kill them? No. These aren't acts of god, but someone very childish and immature who wants to pretend they're god. That's what's going on here. A mass murderer who calls himself Kira exists somewhere. I'm sure of it and I will catch him, but I can't count on Kira making any mistakes.."

L was sure that this Kira person is merely a human and does not belong to the supernatural, but it is quite likely that he's been exposed to supernatural killing methods, as his killing method is physically and mentally impossible. He clearly recognized the degree of danger it possessed and just how lethal it can be.

If this were the case, capturing him was still possible and it would be the only way to determining exactly how he kills by getting him to confess or catching him while doing it. Therefore, finding who Kira is would only be a matter of time if he followed the right strategy and pressured the killer to show up one way or the other.

L has vowed to catch Kira no matter what and to use all his intelligence to win the toughest challenge he has been offered. He would prove to Kira that no real power compares to the power of the human mind, and using that exceptional talent he's been given, he would stop Kira in his tracks at any cost necessary.