  Using local-probe magnetic-characterization techniques of muon spin
relaxation ($\mu$SR) and electron spin resonance (ESR) we have investigated the
Mn-induced magnetism of the wide-bandgap perovskite SrTiO$_3$. Our results
clearly demonstrate that this diluted magnetic oxide (DMO) remains paramagnetic
down to low temperatures for both doping cases, i.e., when Mn substitutes for
Sr or Ti. In addition, both experimental techniques have unveiled that the
distribution of individual Mn$^{2+}$ and Mn$^{4+}$ ions is nonrandom, as these
ions partially aggregate into nanosized clusters.
