Armstrong will practice in the Boston-based firm’s expanding appellate practice.
Armstrong served as chief justice of the Massachusetts Appeals Court from 2000 until 2006. He was appointed to the Appeals Court in 1972 by Governor Francis W. Sargent, and authored 1,682 decisions over the course of his 36 years on the bench.
Dwyer & Collora, which has about 25 lawyers in Boston, specializes in white collar crime.