Commercial litigator Richard C. Schoenstein has joined Pryor Cashman as a partner. He was a partner at Paul, Hastings, Janofsky & Walker.

Geoffrey Potter has joined Patterson Belknap Webb & Tyler as a partner and will head up the firm’s new anti-counterfeiting law practice. He was a counsel at Kramer Levin Naftalis & Frankel.

O’Melveny & Myers has named New York-based partner Bradley J. Butwin as co-chair of the firm’s approximately 550-member litigation department. Los Angeles-based Robert Siegel is the other co-chair.

Winston & Strawn has named New York-based commercial litigation partner David Mol- lón as co-chair of the firm’s diversity committee. Amanda Groves, a litigation partner in San Francisco, is the other co-chair.