Tradition
St. Jerome
De Viris Illustribus (Illustrious Men)
Chapter 14
Justus, of Tiberias of the province Galilee, also attempted to write a History of Jewish affairs and certain brief Commentaries on the Scriptures but Josephus convicts him of falsehood. It is known that he wrote at the same time as Josephus himself.
Source: De Viris Illustribus (Illustrious Men) (New Advent)