A lawyer who has represented several police unions was arrested Friday on charges of groping two female lawyers in his downtown office.

According to the complaint by the Manhattan district attorney’s office, Richard A. Dienst, 67, of Queller, Fisher, Dienst, Serrins, Washer & Kool is facing two counts each of forcible touching, third-degree sexual abuse and second-degree harassment based on separate incidents taking place on June 22, 2007, and March 21, 2008.