People v. Walker, 2017 WL 2672560 (App. Ct. Ill. 2017)

Defendant argues that there was not an adequate foundation for the expert's testimony because he did not take notes during his examination, did not count the number of markings but rather observed the overall pattern, and stated that there is no minimum standard for number of similarities that must be observed. The court holds that the expert's testimony is reliable because he testified based on his experience, using procedures common for firearms identification, and that he did not need to testify to the underlying facts or data before testifying as to his opinion. Since his qualifications as an expert were not challenged, the basis for his testimony goes to the weight, not the admissibility. The court also disagreed with the precedent defendant cited to support that lack of taking notes support lack of basis for the opinion, stating the the case relied upon has been noted by several courts to be an outlier.