The Division found that Lerner improperly charged clients over the course of a decade for $50,000 in car-service rides and that it was “repeated and protracted” in nature, Lerner, who has represented major art-world entities, including the Sonnabend estate and the Gagosian Gallery, is also facing charges that he fraudulently took at least $750,000 in fees from the foundation of the artist Cy Twombly, who died in 2011.