<p>While it was never explicitly stated (to my knowledge) why they discounted the possibility of a 3rd Kira, I can come up with some educated guesses.</p>

<p>First, there was no evidence of a 3rd person acting as Kira while the first two were active.  </p>

<p>Remember that the investigation started by looking into a single Kira.  The second Kira was discovered when Misa sent the video broadcasts as a way to contact the first Kira.  It was also further cemented that the second Kira was different from the first in the way they acted.  The second acted more recklessly (with less well thought out and deliberate actions), killed people that the original Kira would not have and was also shown to be able to kill without a name.  The only way they found out there was a second Kira is because the evidence showed there were two people independently acting as Kira at the same time.  </p>

<p>The "3rd Kira" (Higuchi) acted in the same way as the first Kira.  This was intentional.  Light wanted to use this to alleviate suspicion that he was Kira.  By having Higuchi act the same way, there was no reason to believe that he wasn't the original Kira.  Meaning that when Higuchi was caught, Light should be (theoretically) cleared.</p>

<p>Second, L already had a plethora of evidence that implicated Light as Kira.  As far as L was concerned, Light was Kira.  He just needed a few more details (how Light was killing people, for instance) before he could arrest Light.  </p>

<p>Then Light comes up with the prison scheme.  L is immediately suspicious.  Light was trying hard, almost too hard, to prove his innocence.  And L obviously couldn't take any evidence Light offered at face value.  So even while Light was in prison, L was working on the assumption that Light was Kira.  And when Light's personality underwent a drastic change when he gave up the notebook, it threw a wrench in L's theory.  Light when from a calm denial of being Kira to having a fanatical, emotional denial.  This evidence contradicted the Light-is-Kira theory.  </p>

<p>L is now stuck between a rock and a hard place.  On the one hand, everything points to Light being Kira.  On the other, Light's behavior along with the continued killings seemed to exonerate Light.  And since the behavior change coincided nicely with the killings resuming, the idea of the power transfer was born.  And given that theory, why investigate a 3rd Kira that may not exist (and of which there was little if any evidence of)?</p>

<p>Third, let's play devil's advocate and assume L considered that there was a third Kira.  How did this person get in contact with the first two Kiras?  As far as the task force knew, there would be no special way for one Kira to find another (as evidenced by the second Kira needing to send the broadcasts to locate the original).  Also, how did they communicate and coordinate with Light and Misa?  Light and Misa had been under surveillance for quite a while.  Surely something would have come up that would have raised a few eyebrows, especially given the nature of Misa's messages when trying to find Light?  Additionally, if there was a third Kira, why did he show up now?  Why would he just resume what Kira was doing without making any changes?  (Remember that the connection between Kira (Higuchi) and the Yotsuba group hadn't been discovered yet.)  Every person is different (especially in their values, thinking and reasoning), so there should be at least some subtle differences between two Kiras.  And none of that showed up (yet).</p>

<p>Given all of this, there was no reason to assume a third Kira existed.  Investigating every anomaly by assuming it was a separate person would have led L on a hundred wild goose chases.  L was the best detective in the world.  His experience and knowledge would tell him that something else was going on.  Given that he knew Light and how smart Light was, he could very easily presume that every inconsistency could be Light's doing.  And until proven otherwise, that's what L did.  You don't throw out everything you know to be true because the accused offers an (unverified) piece of evidence of their innocence.  And given the mystic powers of Kira, anything was possible, and equally difficult to verify as being impossible. </p>

CC BY-SA 3.0
2017-10-31T14:33:07.950Z
I agree the correlation between Light changing mood and killings restarting is a strong suggestion for transfer. I have two questions: why would there a need for the third Kird to get in contact with the first two? Moreover, even if the Yotsuba connection hadn't been made, wasn't Higuchi much more methodical than Light before going to prison? (similar to Light in the begining though).
etal
CC BY-SA 3.0
2017-10-31T14:45:03.177Z
@etal Answer to the first question: The third Kira would have had to be in contact with the original Kira (given his (Higuchi) behavior).  It was way too similar to the original Kira to be coincidence.  If he had been working independently, there would have been enough of a difference in how the third Kira operated compared to the original.  That difference didn't exist.  Thus if he really did exist, he would have needed to be receiving orders from the original Kira in order to keep things as consistent as they were.
Becuzz
CC BY-SA 3.0
2017-10-31T14:48:37.460Z
@etal Answer to the second question: Higuchi was only methodical because of what he was ordered to do.  Light (through Rem) ordered Higuchi to write names of criminals, including when and how to kill, etc.  If he disobeyed, Rem would kill him in order to further Light's plan and to save Misa.  Aside from that, Higuchi was free to do as he wanted.  He (and the Yotsuba group) were very careful so as not to arouse suspicion.  If they were caught, they would all go to jail, lose all their power, etc.  It would be easy to be extremely methodical with a council of people checking each other.
Becuzz
CC BY-SA 3.0
2017-10-31T14:59:41.687Z
the point of my second question was to say that there was a difference between 1st Kira and '3rd' Kira; which puts into question the 'continuity' hypothesis.
etal
CC BY-SA 3.0
2017-10-31T15:01:11.877Z
About the 1st question, what behaviour did the 3rd Kira exibit that wouldn't be possible without any contact? I believe being methodical could have been inferred from the news; but there may be other things
etal
CC BY-SA 3.0
2017-10-31T15:26:00.650Z
@etal I'm not sure Higuchi was really that much more methodical than Light.  Both found non-petty criminals whose names and faces had been released on the news and killed them.  Unless there is something I'm forgetting, from the task force's perspective, they behaved exactly the same.
Becuzz
CC BY-SA 3.0
2017-10-31T15:26:07.927Z
@etal As far as behavior that couldn't have been inferred from the news, think about what kinds of things Misa got wrong.  She killed some petty criminals which led to the second Kira theory.  As you've pointed out, Higuchi wasn't the love-struck air-head Misa was.  But remember that the police at certain points didn't release information about the deaths of criminals.  After a certain point, Higuchi would have needed information from Light on numbers of people to kill, types of crimes that warranted death, etc.  That wasn't coming from the news.
Becuzz
CC BY-SA 3.0
2017-10-31T14:04:15.577Z
2017-10-31T14:04:15.577Z
Becuzz
<p>When L captures Misa and Light puts himself in prison and gives up the death note, L and the task force suspect that both of them have 'Kira powers'. Murders stop, which makes them believe Misa and Light were the only ones with Kira powers.</p>

<p>When murders return there could be three reasons:</p>

<ul>
<li>Light and/or Misa were not Kira</li>
<li>Powers were transfered</li>
<li>There are more than 2 kiras.</li>
</ul>

<p>However, they don't consider the third option.</p>

<p>I can see there's a leap between thinking of a single Kira and multiple Kiras. However, given they were already working with the hypothesis of 2 Kiras, why not consider the option of a 3rd Kira (without any power transfer)? This wouldn't discard Light and Misa of still having powers and thus keeping them in custody.</p>

CC BY-SA 4.0
2019-05-22T16:55:27.043Z
It was impossible for L to consider a 3rd Kira especially after he locked up 2 possible Kiras and the killing spree stopped. Simply because that would imply that he would never be able to solve this case and end Kira's rampage. This might not be the whole reason and it might not be 100% canon but it is hinted at several times. (Misas fake reply to the faked reply to her call for Kira, Ls own thoughts and comments regarding the way the "power" might be obtained, ...)
hajef
<death-note>
Why not consider possibility of 3rd Kira when Misa and Light in prison?
# Why not consider possibility of 3rd Kira when Misa and Light in prison?
Posted by: username_0 on 2017-10-31
When L captures Misa and Light puts himself in prison and gives up the death note, L and the task force suspect that both of them have 'Kira powers'. Murders stop, which makes them believe Misa and Light were the only ones with Kira powers.

When murders return there could be three reasons:

* Light and/or Misa were not Kira
* Powers were transfered
* There are more than 2 kiras.

However, they don't consider the third option.

I can see there's a leap between thinking of a single Kira and multiple Kiras. However, given they were already working with the hypothesis of 2 Kiras, why not consider the option of a 3rd Kira (without any power transfer)? This wouldn't discard Light and Misa of still having powers and thus keeping them in custody.
**Tags:** death-note
> **Comments:**
> **username_1**: It was impossible for L to consider a 3rd Kira especially after he locked up 2 possible Kiras and the killing spree stopped. Simply because that would imply that he would never be able to solve this case and end Kira's rampage. This might not be the whole reason and it might not be 100% canon but it is hinted at several times. (Misas fake reply to the faked reply to her call for Kira, Ls own thoughts and comments regarding the way the "power" might be obtained, ...)  
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## 1 answers
### Answer by username_2 on 2017-10-31. Score: 5
While it was never explicitly stated (to my knowledge) why they discounted the possibility of a 3rd Kira, I can come up with some educated guesses.

First, there was no evidence of a 3rd person acting as Kira while the first two were active.

Remember that the investigation started by looking into a single Kira. The second Kira was discovered when Misa sent the video broadcasts as a way to contact the first Kira. It was also further cemented that the second Kira was different from the first in the way they acted. The second acted more recklessly (with less well thought out and deliberate actions), killed people that the original Kira would not have and was also shown to be able to kill without a name. The only way they found out there was a second Kira is because the evidence showed there were two people independently acting as Kira at the same time.

The "3rd Kira" (Higuchi) acted in the same way as the first Kira. This was intentional. Light wanted to use this to alleviate suspicion that he was Kira. By having Higuchi act the same way, there was no reason to believe that he wasn't the original Kira. Meaning that when Higuchi was caught, Light should be (theoretically) cleared.

Second, L already had a plethora of evidence that implicated Light as Kira. As far as L was concerned, Light was Kira. He just needed a few more details (how Light was killing people, for instance) before he could arrest Light.

Then Light comes up with the prison scheme. L is immediately suspicious. Light was trying hard, almost too hard, to prove his innocence. And L obviously couldn't take any evidence Light offered at face value. So even while Light was in prison, L was working on the assumption that Light was Kira. And when Light's personality underwent a drastic change when he gave up the notebook, it threw a wrench in L's theory. Light when from a calm denial of being Kira to having a fanatical, emotional denial. This evidence contradicted the Light-is-Kira theory.

L is now stuck between a rock and a hard place. On the one hand, everything points to Light being Kira. On the other, Light's behavior along with the continued killings seemed to exonerate Light. And since the behavior change coincided nicely with the killings resuming, the idea of the power transfer was born. And given that theory, why investigate a 3rd Kira that may not exist (and of which there was little if any evidence of)?

Third, let's play devil's advocate and assume L considered that there was a third Kira. How did this person get in contact with the first two Kiras? As far as the task force knew, there would be no special way for one Kira to find another (as evidenced by the second Kira needing to send the broadcasts to locate the original). Also, how did they communicate and coordinate with Light and Misa? Light and Misa had been under surveillance for quite a while. Surely something would have come up that would have raised a few eyebrows, especially given the nature of Misa's messages when trying to find Light? Additionally, if there was a third Kira, why did he show up now? Why would he just resume what Kira was doing without making any changes? (Remember that the connection between Kira (Higuchi) and the Yotsuba group hadn't been discovered yet.) Every person is different (especially in their values, thinking and reasoning), so there should be at least some subtle differences between two Kiras. And none of that showed up (yet).

Given all of this, there was no reason to assume a third Kira existed. Investigating every anomaly by assuming it was a separate person would have led L on a hundred wild goose chases. L was the best detective in the world. His experience and knowledge would tell him that something else was going on. Given that he knew Light and how smart Light was, he could very easily presume that every inconsistency could be Light's doing. And until proven otherwise, that's what L did. You don't throw out everything you know to be true because the accused offers an (unverified) piece of evidence of their innocence. And given the mystic powers of Kira, anything was possible, and equally difficult to verify as being impossible.
> **Comments:**
> **username_0** (2017-10-31): I agree the correlation between Light changing mood and killings restarting is a strong suggestion for transfer. I have two questions: why would there a need for the third Kird to get in contact with the first two? Moreover, even if the Yotsuba connection hadn't been made, wasn't Higuchi much more methodical than Light before going to prison? (similar to Light in the begining though).  
> **username_2** (2017-10-31): @etal Answer to the first question: The third Kira would have had to be in contact with the original Kira (given his (Higuchi) behavior).  It was way too similar to the original Kira to be coincidence.  If he had been working independently, there would have been enough of a difference in how the third Kira operated compared to the original.  That difference didn't exist.  Thus if he really did exist, he would have needed to be receiving orders from the original Kira in order to keep things as consistent as they were.  
> **username_2** (2017-10-31): @etal Answer to the second question: Higuchi was only methodical because of what he was ordered to do.  Light (through Rem) ordered Higuchi to write names of criminals, including when and how to kill, etc.  If he disobeyed, Rem would kill him in order to further Light's plan and to save Misa.  Aside from that, Higuchi was free to do as he wanted.  He (and the Yotsuba group) were very careful so as not to arouse suspicion.  If they were caught, they would all go to jail, lose all their power, etc.  It would be easy to be extremely methodical with a council of people checking each other.  
> **username_0** (2017-10-31): the point of my second question was to say that there was a difference between 1st Kira and '3rd' Kira; which puts into question the 'continuity' hypothesis.  
> **username_0** (2017-10-31): About the 1st question, what behaviour did the 3rd Kira exibit that wouldn't be possible without any contact? I believe being methodical could have been inferred from the news; but there may be other things  
> **username_2** (2017-10-31): @etal I'm not sure Higuchi was really that much more methodical than Light.  Both found non-petty criminals whose names and faces had been released on the news and killed them.  Unless there is something I'm forgetting, from the task force's perspective, they behaved exactly the same.  
> **username_2** (2017-10-31): @etal As far as behavior that couldn't have been inferred from the news, think about what kinds of things Misa got wrong.  She killed some petty criminals which led to the second Kira theory.  As you've pointed out, Higuchi wasn't the love-struck air-head Misa was.  But remember that the police at certain points didn't release information about the deaths of criminals.  After a certain point, Higuchi would have needed information from Light on numbers of people to kill, types of crimes that warranted death, etc.  That wasn't coming from the news.  
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