See, this is the problem with laymen analyzing criminal justice.
1. Per what statutes were they prosecuted?
1A. What does the statute state? What are its predicates?
2. In what states were they prosecuted?
3. What evidence was presented?
4. How was the evidence argued by the prosecution and the defense?
5. Were they bench trials or a jury trials?
6. Were they plea-bargained?
All legitimate questions (arguments), but when presented in the local newspaper what conclusions would you come to? BTW, number 3 is someone I know.
In addition to the factors that olivant has listed, the defendant's prior record can significantly alter the sentencing guidelines. In PA we weigh the gravity of the offfense (each offense has a gravity score from 1-10) against the prior record score to get standard, mitigated and aggravated ranges of sentences. If the judge departs from the guidelines, especially if he goes into the high aggravated range or beyond, he or she better state the reasons on the record.
You noted that the cop, who killed his wife and fabricated a defense of self-defense, got off light. For the most part I have found that peace officers, who are sentenced for crimes that do not involve a breach of their duties as officers, get mitigated sentences.
