  A model-dependent analysis of the hadronic substructure in tau- -> pi- pi-
pi+ neutrino decay is reported. The decay is dominated by the process tau- ->
a1(1260)- + neutrino, in which a1(1260)- -> rho0 pi- in an S-wave decay.
Amplitudes involving a1(1260) decays into isoscalars, especially a_1(1260)- ->
f0(600)pi-, are large. tau- -> pi- pi- pi+ neutrino decays via the pseudoscalar
pi(1300)- are small. These results support the resonant substructure reported
in the previously reported analysis of tau- -> pi0 pi0 pi- neutrino decay mode
from the same CLEO II data sample.
