  We consider the spatial offsets of short hard gamma-ray bursts (SHBs) from
their host galaxies. We show that all SHBs with extended duration soft emission
components lie very close to their hosts. We suggest that NS-BH binary mergers
offer a natural explanation for the properties of this extended duration/low
offset group. SHBs with large offsets have no observed extended emission
components and are less likely to have an optically detected afterglow,
properties consistent with NS-NS binary mergers occurring in low density
environments.
