A few days before the fire, I personally ran into a woman who matched the description of the woman with the gas can very close to the burn area. She was lurking in bushes on private property and I compelled her to leave. She looked like a dude until you got up close - obviously Lesbian. Her eyes/expression looked INSANE at the time and I kept by distance and tried to be as polite as I could because I sensed she was highly tense (coming off meth most likely). 

It was probably the same woman who started the fire (to "get back at" society no doubt) and because the cops knew she was homeless, they deliberately didn't want to pursue her as a suspect. So she was allowed to leave the neighborhood carrying the gas can without being even detained nor questioned by LAPD.