It goes without saying that Roman Polanski's 70s statutory rape (it is rape, whether consensual or forced) of a 13-year-old girl (with a mother who wanted her to be a part of Show Business) was a crime.
And Polanski spent 42 days in Chino prison for "psychological evaluation." A plea deal was created ; the 42 days was to be the entirety of his punishment. Then the judge reneged upon the decision--and Polanski chose to flee the US.
Like him or not, Roman Polanski (in exile from both the US and the UK for over three decades) has been punished enough.
There are more recent crimes that the Los Angeles District Attorney's office should marshal its resources towards prosecuting--rather than trying to "win" an old case that (even the victim agrees) should be put behind us now.