While the host galaxies of short-duration GRBs tell a relatively consistent story, perhaps the strongest circumstantial evidence connecting them to binary neutron star mergers comes from the distribution of offsets, i.e., the distance of the GRB from its host nucleus.  Because their massive star progenitors have very short lifetimes, long-duration GRBs explode in the dense star forming regions in which they were formed.  As a result, the typical physical offset for a long-duration GRB is quite small, ~ 1 kpc.  Longer-lived progenitors, particularly those with large kick velocities, would naturally be expected to have larger physical offsets \cite{Bloom_2002}.