Library Eusebius of Caesarea Church History
Book 2, Chapter 7: Pilate's Suicide.
It is worthy of note that Pilate himself, who was governor in the time of our Saviour, is reported to have fallen into such misfortunes under Caius, whose times we are recording, that he was forced to become his own murderer and executioner; and thus divine vengeance, as it seems, was not long in overtaking him. This is stated by those Greek historians who have recorded the Olympiads, together with the respective events which have taken place in each period.
English translation by Arthur Cushman McGiffert, in Nicene and Post-Nicene Fathers, Series II, Vol. I (eds. Philip Schaff and Henry Wace; Buffalo: Christian Literature Publishing Co., 1890). Public domain. Digital text via New Advent Church Fathers.