First, contra some of the headlines, there's no question of "child molestation" here. Lewis was 16 at the time she alleges the incident occurred. The "age of consent" in France is 15.
Photo from fOTOGLIF
Although Polanski, 76, was accused of "forcing himself" upon Lewis, the actress pointedly did not use the word "rape." "The words we used are the words we used," Allred said when asked about the actress's allegations.
Thirdly, Lewis was so traumatized by the incident that she
This pretty much screams "casting couch sex" rather than "rape" (a word which Lewis declined to use) or "child molestation" (for purposes of sexual consent, she was legally an adult at the time).
For the record, I am not, repeat not, saying that's not a bad thing. A powerful older film director abusing his possible ability to make or break careers to intimidate his way into a 16-year-old actor's panties is indeed a bad thing. But it's not the same kind of bad thing as drugging and raping a 13-year-old.
So, why come out with it now instead of 28 years ago?
It isn't for the purpose of pressing charges. The statute of limitations in France is 10 years for child sexual assault; I doubt that it's as long, or at least any longer, for rape of a putative adult.
It's obviously not because she wants to protect prospective future victims of the Evil Polanski. Everybody already knows about him and has for a long time, and if you're trying to stop a victimizer from victimizing you don't give him a 28-year head start.
The idea that she wants Polanski's "additional history" taken into consideration at sentencing rings hollow. If she'd come out with her story earlier, it would have had the same effect -- and it might well have deprived him of his 32 years of refuge in France.
That leaves the two obvious things:
1) Money. If Polanski goes down and is incarcerated, he can be served, compelled to appear, and will be in no position to move his wealth around to protect it. Expect a number of actual or alleged victims to pop up with civil suits aimed at getting a piece of his fortune. Who wouldn't expect to see Allred jockeying for pole position in that litigation queue?
2) Buzz. Lewis hasn't racked an IMDB-worthy acting credit since 2003. Now she's in the headlines and possibly on tap to come to California to give high-profile testimony.