The perjury is a felony in and of itself and the death that resulted from commission of that felony would be a capital murder in a lot of jurisdictions.
The witness tampering would surely inflame jurors and increase the likelihood of a guilty verdict.
Although it surprises me (but does not disappoint me) that they were charged, what they have now is a bargain compared to what they would have received in a trial.
Actually it's a Federal Crime which carries the death penalty.
TITLE 18, U.S.C., SECTION 242
Whoever, under color of any law, statute, ordinance, regulation, or custom, willfully subjects any person in any State, Territory, Commonwealth, Possession, or District to the deprivation of any rights, privileges, or immunities secured or protected by the Constitution or laws of the United States, ... shall be fined under this title or imprisoned not more than one year, or both; and if bodily injury results from the acts committed in violation of this section or if such acts include the use, attempted use, or threatened use of a dangerous weapon, explosives, or fire, shall be fined under this title or imprisoned not more than ten years, or both; and if death results from the acts committed in violation of this section or if such acts include kidnaping or an attempt to kidnap, aggravated sexual abuse, or an attempt to commit aggravated sexual abuse, or an attempt to kill, shall be fined under this title, or imprisoned for any term of years or for life, or both, or may be sentenced to death.
But since they're cops, they'll only get ten years.
L