Proposition 47’s new definition of “unreasonable risk of danger to public safety” (Pen. Code, § 1170.18, subd. (c)) does not apply retroactively to an appeal from a Proposition 36 resentencing denial. Chaney was sentenced under the Three Strikes Law to 25 years to life. After the Three Strikes Reform Act passed, he petitioned for resentencing, but the superior court denied relief on the basis that he posed an unreasonable risk of danger to public safety. (Pen. Code, § 1170.126, subd. (g).) Chaney appealed and the Court of Appeal affirmed. Shortly thereafter, California voters enacted Proposition 47, which included a new definition of “unreasonable risk of danger to public safety.” (See Pen. Code, § 1170.18, subd. (c), enacted by Proposition 47.) Section 1170.18, subdivision (c) provides that “As used throughout this Code, ‘unreasonable risk of danger to public safety’ means an unreasonable risk that the petitioner will commit a new violent felony within the meaning of [Penal Code section 667, subdivision (e)(2)(C)(iv)].” Chaney petitioned for rehearing, arguing that he did not pose an unreasonable risk of danger to public safety under the new definition of that term contained in Proposition 47, which should retroactively apply in his case pursuant to In re Estrada (1965) 63 Cal.2d 740. Held: Rehearing denied and opinion modified. Penal Code section 3 provides that “[n]o part of [the Penal Code] is retroactive, unless expressly so declared” and Proposition 47 does not expressly declare that its new definition of unreasonable risk of danger is retroactive. Although Estrada recognizes an exception to this rule for statutes that “lessen punishment,” the court held that the new definition of unreasonable risk of danger did not lessen punishment because it only “changes the lens through which the dangerousness determinations under the Act are made.” [Editor’s Note: In a footnote, the court noted that it was not deciding whether the definition of “unreasonable risk of danger to public safety” in Proposition 47 applies prospectively to petitions for resentencing under the Reform Act.]