Pliny was governor of Pontus/Bithynia. His letter to the Emperor Trajan in 112 AD is the first pagan reference to Christianity. I thought you might find parts of the letter interesting, and have listed excerpts from it here.
…In the case of those who were denounced to me as Christians, I have observed the following procedure: I interrogated these as to whether they were Christians; those who confessed I interrogated a second and a third time, threatening them with punishment; those who persisted I ordered executed. For I had no doubt that, whatever the nature of their creed, stubbornness and inflexible obstinacy surely deserve to be punished…
The sum and substance of their fault or error had been that they were accustomed to meet on a fixed day before dawn and sing responsively a hymn to Christ as to a god,…When this was over, it was their custom to depart and to assemble again to partake of food…
The matter seemed to me to warrant consulting you, especially because of the number involved. For many persons of every age, every rank, and also of both sexes are and will be endangered. For the contagion of this superstition has spread not only to the cities but also to the villages and farms.