That same consulship witnessed a horrible instance of misery and brutality.
A father as defendant, a son as prosecutor, (Vibius Serenus was the
name of both) were brought before the Senate; the father, dragged
from exile in filth and squalor now stood in irons, while the son
pleaded for his guilt. With studious elegance of dress and cheerful
looks, the youth, at once accuser and witness, alleged a plot against
the emperor and that men had been sent to Gaul to excite rebellion,
further adding that Caecilius Cornutus, an ex-praetor, had furnished
money. Cornutus, weary of anxiety and feeling that peril was equivalent
to ruin, hastened to destroy himself. But the accused with fearless
spirit, looked his son in the face, shook his chains, and appealed
to the vengeance of the gods, with a prayer that they would restore
him to his exile, where he might live far away from such practices,
and that, as for his son, punishment might sooner or later overtake
him. He protested too that Cornutus was innocent and that his terror
was groundless, as would easily be perceived, if other names were
given up; for he never would have plotted the emperor’s murder and
a revolution with only one confederate.

Upon this the prosecutor named Cneius Lentulus and Seius Tubero, to
the great confusion of the emperor, at finding a hostile rebellion
and disturbance of the public peace charged on two leading men in
the state, his own intimate friends, the first of whom was in extreme
old age and the second in very feeble health. They were, however,
at once acquitted. As for the father, his slaves were examined by
torture, and the result was unfavourable to the accuser. The man,
maddened by remorse, and terror-stricken by the popular voice, which
menaced him with the dungeon, the rock, or a parricide’s doom, fled
from Rome. He was dragged back from Ravenna, and forced to go through
the prosecution, during which Tiberius did not disguise the old grudge
he bore the exile Serenus. For after Libo’s conviction, Serenus had
sent the emperor a letter, upbraiding him for not having rewarded
his special zeal in that trial, with further hints more insolent than
could be safely trusted to the easily offended ears of a despot. All
this Tiberius revived eight years later, charging on him various misconduct
during that interval, even though the examination by torture, owing
to the obstinacy of the slaves, had contradicted his guilt.

The Senate then gave their votes that Serenus should be punished according
to ancient precedent, when the emperor, to soften the odium of the
affair, interposed with his veto. Next, Gallus Asinius proposed that
he should be confined in Gyaros or Donusa, but this he rejected, on
the ground that both these islands were deficient in water, and that
he whose life was spared, ought to be allowed the necessaries of life.
And so Serenus was conveyed back to Amorgus.

In consequence of the suicide of Cornutus, it was proposed to deprive
informers of their rewards whenever a person accused of treason put
an end to his life by his own act before the completion of the trial.
The motion was on the point of being carried when the emperor, with
a harshness contrary to his manner, spoke openly for the informers,
complaining that the laws would be ineffective, and the State brought
to the verge of ruin. “Better,” he said, “to subvert the constitution
than to remove its guardians.” Thus the informers, a class invented
to destroy the commonwealth, and never enough controlled even by legal
penalties, were stimulated by rewards.

Some little joy broke this long succession of horrors. Caius Cominius,
a Roman knight, was spared by the emperor, against whom he was convicted
of having written libellous verses, at the intercession of his brother,
who was a Senator. Hence it seemed the more amazing that one who knew
better things and the glory which waits on mercy, should prefer harsher
courses. He did not indeed err from dulness, and it is easy to see
when the acts of a sovereign meet with genuine, and when with fictitious
popularity. And even he himself, though usually artificial in manner,
and though his words escaped him with a seeming struggle, spoke out
freely and fluently whenever he came to a man’s rescue.

In another case, that of Publius Suillius, formerly quaestor to Germanicus,
who was to be expelled from Italy on a conviction of having received
money for a judicial decision, he held that the man ought to be banished
to an island, and so intensely strong was his feeling that he bound
the Senate by an oath that this was a State necessity. The act was
thought cruel at the moment, but subsequently it redounded to his
honour when Suillius returned from exile. The next age saw him in
tremendous power and a venal creature of the emperor Claudius, whose
friendship he long used, with success, never for good.
The Annals by Tacitus