What is the evidence used to determine whether a street gang is a criminal street gang?

It is information upon which experts in the field can rely in opining whether the organization in question is a criminal street gang within the meaning of section 186.22. Moreover, such information is not considered testimonial for confrontation clause purposes. (See People v. Valadez (2013) 220 Cal.App.4th 16, 32-36, 162 Cal.Rptr.3d 722 [general background information obtained from gang members, other officers, and written materials on the history of the gang used by experts in the field is not testimonial].) Forgoing an objection to this evidence was not deficient performance.