PORTLAND, Ore. (AP) — U.S. Attorney Billy J. Williams will step down from his job as top federal prosecutor in Oregon at the end of the month. Williams, a 20-year U.S. Justice Department veteran, was first appointed by President Barack Obama in 2015 and reappointed by President Donald Trump in 2017 — and unusual move in a presidential transition. Williams oversaw the high-profile acquittal of Ammon and Ryan Bundy, brothers who staged a 2016 armed takeover of the Malheur National Wildlife Refuge. He also oversaw the trial and acquittal of an FBI agent who was accused of firing shots during that occupation.