When it comes to the sexual assault of a minor of any age (but especially pre-pubescent minors), there should be no statute of limitations. Period.
Because I genuinely believe in the eternal nature of life, I do not approve of the death penalty for any reason. Life in prison, however, is fine.
This is my notion of the kind of prison designed solely for rapists and murderers:
No parole. No appeals. No connection to the outside world. No phone. No TV. No communication with any other human. Solitary confinement in a space with a bed, toilet, shower, and very small window to let in the light of day, but not big enough for them to escape through. It would have an insect screen, and be opened for fresh air via pushbutton. Humane temperature-controlled environment. No time outside. One book of their choice.
It's the same as death, but no one else has to do the honor killing. Less expensive than years of attorneys and appeals courts, not to mention the executioner.