  We present a new suite of photometric and spectroscopic data for the faint
Bootes II dwarf spheroidal galaxy candidate. Our deep photometry, obtained with
the INT/WFC, suggests a distance of 46 kpc and a small half-light radius of 4.0
arcmin (56 pc), consistent with previous estimates. Follow-up spectroscopy
obtained with the Gemini/GMOS instrument yielded radial velocities and
metallicities. While the majority of our targets covers a broad range in
velocities and metallicities, we find five stars which share very similar
velocities and metallicities and which are all compatible with the colors and
magnitudes of the galaxy's likely red giant branch. We interpret these as a
spectroscopic detection of the Bootes II system. These stars have a mean
velocity of -117 km/s, a velocity dispersion of (10.5+-7.4) km/s and a mean
[Fe/H] of -1.79 dex, with a dispersion of 0.14 dex. At this metallicity, Boo II
is not consistent with the stellar-mass-metallicity relation for the more
luminous dwarf galaxies. Coupled with our distance estimate, its high negative
systemic velocity rules out any physical connection with its projected
neighbor, the Bootes I dwarf spheroidal, which has a velocity of ~+100 km/s.
The velocity and distance of Bootes II coincide with those of the leading arm
of Sagittarius, which passes through this region of the sky, so that it is
possible that Bootes II may be a stellar system associated with the Sagittarius
stream. Finally, we note that the properties of Bootes II are consistent with
being the surviving remnant of a previously larger and more luminous dSph
galaxy.
