Laudator Temporis Acti

Anthony J. Marshall, "Symbols and Showmanship in Roman Public Life: The Fasces," Phoenix 38.2 (1984) 120-141 (at 130-131, footnotes omitted):

We may take our start from the basic fact that the fasces were not merely decorative or symbolic devices carried before magistrates in a parade of idle formalism. Rather, they constituted a portable kit for flogging and decapitation. Since they were so brutally functional, they not only served as ceremonial symbols of office but also carried the potential of violent repression and execution.

[....]

Slaves or free men unprotected by citizenship or special privilege were subject without appeal to the full powers of the imperium administered via the lictor's strong right arm. This might run to a few blows to control crowds or enforce respect for the magistrate at an assize-hearing, or it might extend to flogging with or without decapitation to follow. Although the virgae themselves were not intended for capital punishment, the fasces are sometimes termed "bloody" in our sources because of the terrible beating which the heavy rods inflicted; they could, and sometimes did, prove lethal. Of birch or elmwood and some one-and-a-half meters in length, they were considerably weightier than the centurion's vitis or "swagger-stick," (which it was permissible to apply to citizens' backs). The virgae could of course be used on non-Roman military personnel. The single-headed securis, regularly carried in the fasces extra urbem and seen as a component of the regalia of office, was employed for executions under the Republic, later replaced in the Principate by the sword. Condemned prisoners were not kept waiting after sentencing, and execution was carried out in full public view. When the magistrate bade the praeco pronounce the dread words age lege, the lictors would unstrap the red thongs of the fasces on the spot (virgas expedire).