  We have carried out a systematic search for recoiling supermassive black
holes (rSMBH) using the Chandra Source and SDSS Cross Matched Catalog. From the
survey, we have detected a potential rSMBH, 'CXO J101527.2+625911' at z=0.3504.
The CXO J101527.2+625911 has a spatially offset (1.26$\pm$0.05 kpc) active SMBH
and kinematically offset broad emission lines (175$\pm$25 km s$^{\rm -1}$
relative to systemic velocity). The observed spatial and velocity offsets
suggest this galaxy could be a rSMBH, but we also have considered a possibility
of dual SMBH scenario. The column density towards the galaxy center was found
to be Compton thin, but no X-ray source was detected. The non-detection of the
X-ray source in the nucleus suggests either there is no obscured actively
accreting SMBH, or there exists an SMBH but has a low accretion rate (i.e.
low-luminosity AGN (LLAGN)). The possibility of the LLAGN was investigated and
found to be unlikely based on the H$\alpha$ luminosity, radio power, and
kinematic arguments. This, along with the null detection of X-ray source in the
nucleus supports our hypothesis that the CXO J101527.2+625911 is a rSMBH. Our
GALFIT analysis shows the host galaxy to be a bulge-dominated elliptical. The
weak morphological disturbance and small spatial and velocity offsets suggest
that CXO J101527.2+625911 could be in the final stage of merging process and
about to turn into a normal elliptical galaxy.
