The Officers are in trouble because they broke(or are accused of breaking) Policy and Procedures(P&P), no different then any other Officer or Deputy in this nation, LEO's are not Judge, Jury and Executioners, they are Law Enforcement Officers who are ruled by the book of laws and Policy and Procedures of the respective departments they work for. If in fact they are outside of P&P then they are subject to the broad hand of justice without the support of their department, again, just like any other LEO in this country.
As a person in Law Enforcement who works in a jail, we make our rounds specifically to prevent these types of incidents, very often we fail but that is why P&P's are there, to protect us, just like when Road LEO's get into shootings they are ruled good or not good shootings according to the P&P's of the department, if these Officers had done their jobs properly I can't say they would have saved this monsters life, but I can say they would not be in this predicament, P&P is there to protect LEO's, but if you are outside of P&P it will hit you like a Mack truck.