There are alternatives to a human killer which would provide some opportunity to make headway, which do not have priors that are obviously lower than a human with a supernatural weapon, such as extraterrestrials or some sort of supernatural creature which is humanly beatable.
The first point where I got really pissed off though was when L jumps all the way to "the killer must know the victim's real name" based on the murder of Lind L. Tailor. Lind L. Tailor was a convicted criminal, and L. wasn't, and killing criminals was already Kira's suspected modus operandi. It was not just possible, but probable, that Kira wouldn't react to a non-criminal's threat to apprehend him (it could have been against protocol, against his/her/it's moral code, unnecessary because Kira is completely unassailable, rejected as unnecessary because Kira is confident enough to think he/she/it is unassailable, etc,) even if doing so was entirely within Kira's abilities. And even if we take for granted that Kira would want to kill L, and assume that Kira has magic action-at-a-distance murder powers, but not magic action-at-a-distance information gathering powers, then whether the victim's name is known or not is just one variable that's flipped between L and Lind L. Tailor. L could just as well have been impervious because he eats too many sweets.
... Good rational answers always seem obvious in retrospect, don't they...
The results for these have been stable for a while now; I'm posting them a bit late. 95 people took the survey after I modified it to add two questions. For the public version, I removed the pre-change data (10 data points).
One text response included identifying information, which I removed in the public version of the data. If you participated and there is any information you provided that you would like removed from the public version, PLEASE tell me as soon as possible and I will remove it.
P.S. To the person who predicted an 80-90% significant difference between different parts of California: I predict with at least 90% confidence that there will be no significant difference, because of the wide spread of locations and smallish sample size of this survey.
(The original post about the survey.)
EDIT: After some comments that it was unethical for me to post the data (in particular the text), I removed public access from the link provided earlier. Given my precommitment to post the data, I assumed it was clear enough to respondents that it would be public. I'm not convinced that this has hurt anyone, but given that others seem to disagree, it seemed prudent to remove it. Please feel free to continue this discussion; I'm interested in your thoughts.