Regardless of their age, 28 years is more than enough time in prison for any crime.
Our society sometimes looks like something Charles Dickens wrote about (or worse). Bringing back the old punishments (drawing & quartering, hanging, etc.) might help, but I doubt it.
A Brit once told me that it was very effective in helping one to focus. He claimed that his caning in mathematics class was responsible for his Ph.D. in math.
The court's role here should be to sentence in a way that a) offsets the incentives that exist for corruption, and b) provides restitution where possible.
The problem is not evil individuals, but that incentives for corruption exist in the first place.