Rush to judgement in San Bernardino? Or another big fat lie?

Twenty-four hours ago the FBI said they had no clue what motivated the San Bernardino shootings & it would be a lengthy process to comb through social media & other evidence to learn. Now, on the basis of a single pro-ISIS posting on Facebook by the woman shooter, they’re zeroing in on terrorism as the motive. Is that the scientific method?

Anybody else get the impression that a narrative is being constructed to fit a purpose? Because when the FBI has investigated crimes like the murder of Trayvon Martin, Michael Brown, & other victims in the Black community, it took months & sometimes years. Is this not a rush to judgement but rather a deception? Because to be persuasive it will take a lot more than a Facebook post.