  Short-hard gamma-ray bursts (SHBs) may arise from gravitational wave (GW)
driven mergers of double neutron star (DNS) systems. DNSs may be "primordial"
or can form dynamically by binary exchange interactions in globular clusters
during core-collapse. For primordial binaries, the time delay between formation
and merger is expected to be short, tau~0.1 Gyr, implying that the redshift
distribution of merger events should follow that of star-formation. We point
out here that for dynamically formed DNSs, the time delay between
star-formation and merger is dominated by the cluster core-collapse time,
rather than by the GW inspiral time, yielding delays comparable to the Hubble
time. We derive the redshift distribution of merger events of dynamically
formed DNSs, and find it to differ significantly from that typically expected
for primordial binaries. The observed redshift distribution of SHBs favors
dynamical formation, although a primordial origin cannot be ruled out due to
possible detection biases. Future red-shift observations of SHBs may allow to
determine whether they are dominated by primordial or dynamically formed DNSs.
