[3] The implication was that anyone who killed him was considered as performing a sacred duty and enjoyed impunity.
These plebeian institutions were extra-legal in that they were not recognised by the senate and the Roman state, which were controlled by the patricians.
Moreover, formally, legislation was supposed to be proposed by the consuls (the two annually elected heads of the Republic) and put to the vote of the Comitia Centuriata, the Assembly of the Soldiers.
The invocation of a religious law provided the justification and sacrosanctity conferred impunity.
These tribunes provided protection from arbitrary coercion by public officials though auxilium (assistance) by personal intervention to stop the action.
They also could use coercitio, the enforcement of their will by coercion through which they could impose fines, imprisonment or the death penalty on anyone who challenged them or abused them verbally or assaulted them.