In 1981 Roger Walters approached a 13-year old girl and lured her into his vehicle by offering her money to help him find a fictitious white dog. He then kidnapped, raped, and sodomized the girl. In 1987, not long after having been released from prison for these crimes, Walters approached a 13-year old girl and attempted to lure her into his vehicle by offering her money to help him find a fictitious white dog. He was arrested, tried and convicted on charges of attempted kidnapping, attempted rape, and attempted sodomy. After the Supreme Court of Oregon unanimously upheld his convictions and sentence, Walters filed the instant petition for a writ of habeas corpus in federal district court. The district court denied relief and Walters has appealed, arguing that he was denied his right to a fair trial, that the evidence was insufficient to support his conviction, and that he was improperly sentenced. We reject each of these contentions and affirm.
I
Walters first argues that the state trial court’s admission of evidence of his 1981 crimes at the trial of the 1987 offenses deprived him of his right to a fair trial. Oregon Evidence Rule 404(3), which is virtually identical to Fed.R.Evid. 404(b), expressly provides that “[e]videnee of other crimes, wrongs or acts ... may ... be admissible for ... proof of motive, opportunity, intent, preparation, plan, knowledge, identity, or absence of mistake or accident.” Or.Rev.Stat. § 40.170, Rule 404(3). We recently upheld under Fed.R.Evid. 404(b) the admission of similar evidence regarding a prior sexual assault when the earlier act was not too remote in time and the trial court gave a limiting instruction. See United States v. Sneezer, 983 F.2d 920, 924 (9th Cir.1992) (per curiam), cert. denied, — U.S. -, 114 S.Ct. 113, 126 L.Ed.2d 79 (1993).
Walters’ conduct in 1987 was virtually identical to that of 1981. Moreover, because Walters spent nearly all of the intervening time in prison, his earlier acts cannot be said to have been too remote in time from those of 1987. In addition, the trial court admitted the evidence of the 1981 crimes solely to prove intent and instructed the jury accordingly. As the admission of the evidence was neither arbitrary nor so prejudicial as to have rendered the trial fundamentally unfair, see Colley v. Sumner, 784 F.2d 984, 990 (9th Cir.), cert. denied, 479 U.S. 839, 107 S.Ct. 142, 93 L.Ed.2d 84 (1986), it cannot be said that the district court abused its discretion by admitting the evidence. See Sneezer, 983 F.2d at 924.
*894II
The heart of Walters’ appeal is his contention that the evidence was insufficient to support his conviction on all three attempt charges. A conviction for attempt under Oregon law requires proof beyond a reasonable doubt that the defendant “intentionally en~ gage[d] in conduct which constitute^] a substantial step toward commission of the crime.” Or.Rev.Stat. § 161.405(1); State v. Walters, 311 Or. 80, 84, 804 P.2d 1164, 1167 (en banc), cert. denied, — U.S. -, 111 S.Ct. 2807, 115 L.Ed.2d 979 (1991). A “substantial step” is one which both advances the criminal purpose charged and strongly corroborates the existence of that purpose. Walters, 311 Or. at 85, 804 P.2d at 1167. Accord, United States v. Scott, 767 F.2d 1308, 1311 (9th Cir.1985). Moreover, “it must be ... of such a nature that a reasonable observer, viewing it in context, could conclude beyond a reasonable doubt that it was undertaken in accordance with a design” to commit the particular crime charged. Id. at 1312 (citation and internal quotation omitted). Finally, a substantial step entails “an overt act adapted to, approximating, and which in the ordinary and likely course of things will result in, the commission of the particular crime.” Id. (citation and quotation omitted).
Under Oregon law, “enticement” can constitute a “substantial step” towards criminal attempt. Walters, 311 Or. at 85-86, 804 P.2d at 1167-68. Accord, Model Penal Code' (“MPC”) § 5.01(2)(b) (1985).1 The evidence showed that Walters attempted to lure his intended victim into his truck by fabricating a story about a lost (and nonexistent) dog, promising money to the girl, and then offering her a ride when she refused the offer of money. These facts, when combined with those underlying Walters’ prior conviction, were sufficient to show that his efforts to entice the girl were intended to advance, and were strongly corroborative of, his criminal purpose.2 See Walters, 311 Or. at 84-85, 804 P.2d at 1167; MPC § 5.01(2). Accordingly, we cannot say that, viewing the evidence in a light most favorable to the prosecution, no reasonable trier of fact could have found the necessary elements of the crimes charged beyond a reasonable doubt. See Jackson v. Virginia, 443 U.S. 307, 319, 99 S.Ct. 2781, 2789, 61 L.Ed.2d 560 (1979).
Ill
Walters finally argues that the trial court’s imposition of an enhanced dangerous offender sentence denied him equal protection of the laws and violated the Constitution’s ex post facto clause. Oregon’s dangerous offender statute requires that there be a determination whether a defendant’s conduct “seriously endangered the life or safety of another” before a sentence may be enhanced for such conduct. Or.Rev.Stat. § 161.725(2). The Oregon courts have interpreted this provision to mean that, in a jury trial, the jury as the trier of fact must decide the question of “serious endangerment”. State v. Follett, 88 Or.App. 512, 515, 746 P.2d 236, 237 (1987) (citing and discussing State v. Mitchell, 84 Or.App. 452, 457, 734 P.2d 379, 382, review denied, 303 Or. 590, 739 P.2d 570 (1987)), review denied, 305 Or. 273, 752 P.2d 1219 (1988).
Walters’ trial and sentencing on this point fully comported with the requirements of state law, and his eonclusory allegations fail to establish an equal protection violation. Moreover, Walters was not disadvantaged by a retroactive application of a law passed after the date of his offense, nor was his punishment greater than the law provided therefor at the time he committed the crimes. See, e.g., Collins v. Youngblood, 497 U.S. 37, 41-*89543, 110 S.Ct. 2715, 2718-2720, 111 L.Ed.2d 30 (1990). Finally, any other error is one of state law and does not rise to the level of a federal constitutional violation cognizable by writ of habeas corpus. See Jammal v. Van de Kamp, 926 F.2d 918, 919-20 (9th Cir.1991).
CONCLUSION
We find no error in this record that would justify our granting Walters’ petition for a writ of habeas corpus and thereby effectively overturn the fine opinion of the Supreme Court of Oregon. Accordingly, the decision of the district court is
AFFIRMED.
. Oregon's criminal attempt statute is based on the Model Penal Code version. Walters, 311 Or. at 85, 804 P.2d at 1167.
. Admittedly, the same substantial step was employed to uphold the attempted kidnapping conviction, but we see no basis on which to dispute the Supreme Court of Oregon’s observation that “the same conduct may constitute a substantial step toward the commission of more than one charged crime, as long as that conduct strongly corroborates the actor's criminal purpose underlying each charged crime.” Walters, 311 Or. at 86 n. 9, 804 P.2d at 1168 n. 9. Accordingly, the finding of a "substantial step”, as Oregon defines that term, is appropriate as to both the attempted rape charge and the attempted sodomy charge in view of Walters' prior bad acts and what they tell us about his criminal purpose in the present case.