The expert psychological evaluator was not competent to give a legal conclusion about the nature of an underlying felony; excluding the inadmissible hearsay which was subject to an objection there was still substantial evidence for the initial commitment findings for Mentally Disordered Offender Act (MDO Act) treatment. Here, the only evidence of the underlying conviction, as required by Penal Code section 2962, subdivisions (b) and (e)(2), came from the expert psychological evaluator who perused Baker’s central file and described the arson conviction and the underlying facts. The testimony about the crime of conviction was hearsay which was admitted without objection. There were hearsay objections to questions about the underlying facts and how the arson posed a danger to others. It was error for the trial court to overrule those objections and the expert was not competent to provide answers to the factual question. Further, her expertise did not extend to providing legal conclusions and as such it could not provide substantial evidence. The arson of an inhabited structure does not prove that the offense posed a substantial danger of physical harm to others. However, eliminating the expert’s hearsay, there was other evidence in the form of a probation report that Baker’s brother was treated for smoke inhalation. Although the report was hearsay, there was no objection to it and it therefore could have been relied on as evidence. Because arson is recognized as an inherently dangerous felony, only “slight evidence” is necessary to establish that a specific act of arson posed a substantial risk of injury. Finally, the issue challenging hearsay testimony about Baker’s 90 days of treatment was not the subject of a hearsay objection or an objection that it was not a proper subject for expert testimony. It was not preserved for appeal and the hearsay provided substantial evidence of this element.