(Portland, OR) -- A Yamhill County professional photographer is facing dozens of charges after allegedly sexually abusing young, aspiring models. KATU reports 52-year-old Robert Arnold Koester facing nearly 60 charges in Oregon and California. Police say Koester drugged and sexually assaulted four victims, including one juvenile, in Oregon. He's accused of assaulting at least four more teenage girls in California. Police arrested him near San Diego, California in November. Federal investigators say he likely has more victims and that his crimes likely started as early as 1994.