BOSTON (AP) — A former top federal prosecutor in Massachusetts who led the case against the Boston Marathon bomber has gone into private practice.

William Weinreb, a 20-year-veteran of the U.S. attorney's office in Boston, has joined Quinn Emanuel Urquhart & Sullivan as a partner.

Weinreb was named acting U.S. attorney when Carmen Ortiz stepped down from the post shortly before Republican President Donald Trump took office. He served in the role until now-U.S. Attorney Andrew Lelling was sworn in December.

Weinreb was the lead prosecutor in the case against Dzhokhar Tsarnaev, who was sentenced to death for the deadly Boston Marathon bombings.