  In this paper we revisit the elasto-viscoplastic, strain-softening,
strain-rate hardening, model as a means to avoid strain localization on a
mathematical plane in the case of a Cauchy continuum. In contrast to the work
of previous researchers de Borst and Duretz (2020); Needleman (1988); Sluys and
de Borst (1992); Wang et al. (1997), we assume that both the frequency $\omega$
and the wave number k belong to the complex plane, therefore a different
expression for the dispersion relation is derived. We prove then that under
these conditions strain localization on a mathematical plane is possible. The
above theoretical results are corroborated by numerical analyses, where the
total strain and plastic strain profiles exhibit mesh dependent behavior.
