When a statute has been amended to mitigate the punishment imposed upon conviction, the client must be resentenced to the lighter punishment if the sentence or conviction has been vacated and the client is resentenced for the same offense.[24] A statute violates the ex post facto clause of the federal constitution[25] if it either (a) punishes as a crime an act previously committed that was innocent when done, (b) increases the punishment for a crime after its commission, or (c) deprives an accused of any defense available under the law at the time the act was committed.[26]

[24] People v. Rossi, 18 Cal.3d 295, 299‑300, 134 Cal.Rptr. 64 (1976); In re Estrada, 63 Cal.2d 740, 744‑745, 48 Cal.Rptr. 172 (1965).

[25] U.S. Const., art. I, sec. 9, clause 3 (Congress may not pass ex post facto law); U.S. Const., art. I, sec. 10, clause 1 (state may not pass ex post facto law).

[26] Collins v. Youngblood, 497 U.S. 37, 111 L.Ed.2d 30 (1990).

Second Circuit

EX POST FACTO - CONTROLLING DATE - LAST DATE OF THE OFFENSE ALLEGED IN THE CHARGE
United States v. Broderson, 67 F.3d 452 (2d Cir. 1995); U.S.S.G. 1B1.11(b), comment (n.2) (for Ex Post Facto purposes, controlling date is the last date of the offense, as alleged in indictment).