  Indium-doped SnTe has been of interest because the system can exhibit both
topological surface states and bulk superconductivity. While the enhancement of
the superconducting transition temperature is established, the character of the
electronic states induced by indium doping remains poorly understood. We report
a study of magneto-transport in a series of Sn$_{1-x}$In$_x$Te single crystals
with $0.1\le x \le 0.45$. From measurements of the Hall effect, we find that
the dominant carrier type changes from hole-like to electron-like at
$x\sim0.25$; one would expect electron-like carriers if the In ions have a
valence of $+3$. For single crystals with $x = 0.45$, corresponding to the
highest superconducting transition temperature, pronounced Shubnikov-de Haas
oscillations are observed in the normal state. In measurements of
magnetoresistance, we find evidence for weak anti-localization (WAL). We
attribute both the quantum oscillations and the WAL to bulk Dirac-like hole
pockets, previously observed in photoemission studies, which coexist with the
dominant electron-like carriers.
