The "confirmation" is from the last two comments on the facebook post before it went into Tribute mode. Those two said the LAPD confirmed it. Apparently that's all the other sites aggregating the incident have been using as confirmation as well.
Blogger in the link I sent earlier hasn't found anything to indicate what was claimed from the LAPD herself.
Blogger in the link I sent earlier hasn't found anything to indicate what was claimed from the LAPD herself.