VELLEIUS PATERCULUS, History of Rome
[II.CXII.VII] Hoc fere tempore, Agrippa, qui eodem die quo Tiberius adoptatus ab auo suo naturali erat, et iam ante biennium, qualis esset, apparere coeperat, mira prauitate animi atque ingenii in praecipitia conuersus, patris atque eiusdem aui sui animum alienauit sibi, moxque, crescentibus in dies uitiis, dignum furore suo habuit exitum.
[2.112.7] ... About this time Agrippa who had been adopted by his natural grandfather on the same day as Tiberius, and had already, two years before, begun to reveal his true character, alienated from himself the affection of his father and grandfather, falling into reckless ways by a strange depravity of mind and disposition; and soon, as his vices increased daily, he met the end which his madness deserved.