As part of its concerted effort to build up its Washington, D.C., presence, San Francisco-headquartered Orrick Herrington & Sutcliffe has lured the head of Squire Patton Boggs’ white-collar practice.

Joe Walker arrived at Orrick on Tuesday after leaving Squire Patton on Sept. 3. He is the 10th lateral partner the California firm has hired in its D.C. office in the past two years; the office now stands at about 125 attorneys.