The crime of the Vestal was neither against the gods alone nor against the Pontifex Maximus alone. The trial and execution of the Vestal Virgin was unique because it was simultaneously both a religious rite to drive out the pollution of incestum and a judicial rite for the punishment of treason. The penetrated virgin was a monster and so must be expiated as a prodigium. Yet she sinned willingly and so was a traitor. The trial therefore had two corresponding functions. First, the trial guaranteed the unanimity of the sacrifice, the “absolute faith in the guilt of the surrogate victim.” It separated the Vestal Virgin from the community and increased the sacrificially necessary guilt. She was made responsible for all the evils that occurred in the time of crisis, especially sterility of women and diseases of cattle (note the common witchcraft charges).
Second, the trial served as the disguise necessary to the proper functioning of the sacred. The Greek and Latin sources themselves carefully distinguished between the execution of the Vestals in 215 and 113 and the sacrifice of the two Greeks and two Gauls along with them (see Appendix).
The disguise has worked extraordinarily well. Pliny is not the only one to be unable to convince himself of the possibility of wrongful conviction. Modern authors commenting on the historical texts hold to an oddly naive and credulous style of reporting. The trials and executions of the Vestals are never referred to as – what they so palpably are – human sacrifice.
Holt N. Parker, “Why Were the Vestals Virgins? Or the Chastity of Women and the Safety of the Roman State” (2004)