What is the standard of review for learning information learned via hearsay?

learned via hearsay "unless they are independently proven by competent evidence or are covered by a hearsay exception." ( Id . at pp. 687, 204 Cal.Rptr.3d 102, 374 P.3d 320.) For example, an expert could testify that a diamond is a symbol adopted by a particular street gang because that constitutes general information. However, an expert could not testify that "an associate of the defendant had a diamond tattooed on his arm." The tattoo is case-specific evidence, which would need to be established by a witness who saw the tattoo, or by an authenticated photograph, or it would need to fall within a hearsay exception. ( Id. at p. 677, 687, 204 Cal.Rptr.3d 102, 374 P.3d 320.) We apply the abuse of discretion standard of review. ( People v. Clark (2016) 63 Cal.4th 522, 590, 203 Cal.Rptr.3d 407, 372 P.3d 811.)