The trial court erred in using appellant’s prior juvenile adjudication for violation of Penal Code section 243, subdivision (d), battery with serious bodily injury, as a strike. While it was proper for the trial court to look to the record behind the juvenile adjudication to determine whether appellant’s conduct constituted “assault by any means of force likely to produce great bodily injury,” the evidence did not support a finding that section 243, subdivision (d), came within Welfare and Institutions Code section 707, subdivision (b)(14). The evidence had to show more than that a great bodily injury resulted from the battery. The evidence had to show that the means employed in causing the injury was likely to cause great bodily injury, and here the record was silent on that point.