The reaction gammap --> pi (+)pi (o)n has been measured at MAMI for photon
energies up to 820 MeV. Invariant mass spectra of the particles in the fina
l state (pi (+)n), (pi (o)n), (pi (+)pi (o)) have been determined for sever
al bins of incident photon energy. Differences in pi (+)pi (o) and simultan
eously measured pi (o)pi (o) invariant mass distributions are assigned to a
rho branch of the D-13(1520) nucleon resonance.