
Tacitus was able to draw upon earlier histories that contained material from the public records, official reports, and contemporary comment.
Among other sources Tacitus consulted Cluvius Rufus and Fabius Rusticus (on Nero), and Vipstanus Messalla (on the year 69). He also turned, as far as he felt necessary, to the Senate’s records, the official journal, and such firsthand information as a speech of Claudius, and the personal memoirs of Agrippina the Younger.

a LITTLE BACKGROUND THAT LED UP TO HIS MENTION OF cHRIST AND THE cHRISTIANS:
38 1 There followed a disaster, whether due to chance or to the malice of the sovereign is uncertain — for each version has its sponsors — but graver and more terrible than any other which has befallen this city by the ravages of fire.... (followed by detailed description of this fire)
40 1 Only on the sixth day, was the conflagration brought to an end at the foot of the Esquiline, by demolishing the buildings over a vast area and opposing to the unabated fury of the flames a clear tract of ground and an open horizon. But fear had not yet been laid aside, nor had hope yet returned to the people, when the fire resumed its ravages; in the less congested parts of the city, however; so that, while the toll of human life was not so great, the destruction of temples and of porticoes dedicated to pleasure was on a wider scale. The second fire produced the greater scandal of the two, as it had broken out on Aemilian property of Tigellinus and appearances suggested that Nero was seeking the glory of founding a new capital and endowing it with his own name...
Heading 6
44 1 So far, the precautions taken were suggested by human prudence: now means were sought for appeasing deity, and application was made to the Sibylline books; at the injunction of which public prayers were offered to Vulcan, Ceres, and Proserpine, while Juno was propitiated by the matrons, first in the Capitol, then at the nearest point of the sea-shore, where water was drawn for sprinkling the temple and image of the goddess. Ritual banquets and all-night vigils were celebrated by women in the married state. But neither human help, nor imperial munificence, nor all the modes of placating Heaven, could stifle scandal or dispel the belief that the fire had taken place by order...
Nero substituted culprits:
44 cont... Therefore, to scotch the rumour, Nero substituted as culprits, and punished with the utmost refinements of cruelty, a class of men, loathed for their vices, whom the crowd styled Christians. Christus, the founder of the name, had undergone the death penalty in the reign of Tiberius, by sentence of the procurator Pontius Pilatus, and the pernicious superstition was checked for a moment, only to break out once more, not merely in Judaea, the home of the disease, but in the capital itself, where all things horrible or shameful in the world collect and find a vogue. First, then, the confessed members of the sect were arrested; next, on their disclosures, vast numbers were convicted, not so much on the count of arson as for hatred of the human race.And derision accompanied their end: they were covered with wild beasts' skins and torn to death by dogs; or they were fastened on crosses, and, when daylight failed were burned to serve as lamps by night. Nero had offered his Gardens for the spectacle, and gave an exhibition in his Circus, mixing with the crowd in the habit of a charioteer, or mounted on his car. Hence, in spite of a guilt which had earned the most exemplary punishment, there arose a sentiment of pity, due to the impression that they were being sacrificed not for the welfare of the state but to the ferocity of a single man.

Christus, the founder of the name, had undergone the death penalty in the reign of Tiberius, by sentence of the procurator Pontius Pilatus,
TACITUS ANNALS
Book XV, XLIV
With Bible Parallels
In the fifteenth year of the reign of Tiberius Caesar—when Pontius Pilate was governor of Judea,... (NIV)
luke 3:1
Matthew 27:
23 “Why? What crime has he committed?” asked Pilate. But they shouted all the louder, “Crucify him!”
24 When Pilate saw that he was getting nowhere, but that instead an uproar was starting, he took water and washed his hands in front of the crowd. “I am innocent of this man’s blood,” he said. “It is your responsibility!”
JOHN 19:
12 From then on, Pilate tried to set Jesus free, but the Jewish leaders kept shouting, “If you let this man go, you are no friend of Caesar. Anyone who claims to be a king opposes Caesar.”
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14 It was the day of Preparation of the Passover; it was about noon. “Here is your king,” Pilate said to the Jews.
15 But they shouted, “Take him away! Take him away! Crucify him!” “Shall I crucify your king?” Pilate asked. “We have no king but Caesar,” the chief priests answered.
16 Finally Pilate handed him over to them to be crucified