  We reexamine canonical quantization of the gauged Rarita-Schwinger theory
using the extended theory, incorporating a dimension $\frac{1}{2}$ auxiliary
spin-$\frac{1}{2}$ field $\Lambda$, in which there is an exact off-shell gauge
invariance. In $\Lambda=0$ gauge, which reduces to the original unextended
theory, our results agree with those found by Johnson and Sudarshan, and later
verified by Velo and Zwanziger, which give a canonical Rarita-Schwinger field
Dirac bracket that is singular for small gauge fields. In gauge covariant
radiation gauge, the Dirac bracket of the Rarita-Schwinger fields is
nonsingular, but does not correspond to a positive semi-definite
anticommutator, and the Dirac bracket of the auxiliary fields has a singularity
of the same form as found in the unextended theory. These results indicate that
gauged Rarita-Schwinger theory is somewhat pathological, and cannot be
canonically quantized within a conventional positive semi-definite metric
Hilbert space. We leave open the questions of whether consistent quantizations
can be achieved by using an indefinite metric Hilbert space, by path integral
methods, or by appropriate couplings to conventional dimension $\frac{3}{2}$
spin-$\frac{1}{2}$ fields.
