Penal Code section 311.11 (possession of child pornography) is a "wobbler" meaning it can be a felony or a misdemeanor. Yes, it carries lifetime sex offender registration.
It can be either one. A lot will depend upon the facts and his criminal record as to how the DA will file the charges. This is a case you need an attorney to assist you on. This carries a lifetime sex registration. Do not try to resolve this case alone.
The District Attorney will review the reports and circumstances and make a decision to file as a felony or misdemeanor. A first offense may be punished by imprisonment in the state prison, or a county jail for up to one year, or by a fine not exceeding two thousand five hundred dollars ($2,500), or by both the fine and imprisonment. If convicted, registration is required.