Adjoint L-Functions for GL(3) and U_2,1

We show that the finite part of the adjoint L-function (including contributions from all non-archimedean places, including ramified places) is holomorphic in Re(s) ≥ 1/2 for a cuspidal automorphic representation of GL3 over a number field. This improves the main result of [21]. We obtain more general results for twisted adjoint L-functions of both GL3 and quasisplit unitary groups. For unitary groups, we explicate the relationship between poles of twisted adjoint L-functions, endoscopy, and the structure of the stable base change lifting.