Saris then served as Assistant United States Attorney of the District of Massachusetts from 1982 to 1986. She was Chief of the Civil Division from 1984 to 1986. From 1986 to 1989 she was a United States magistrate judge for the District of Massachusetts. She was an associate justice in the Trial Court of Massachusetts, Superior Court Department from 1989 to 1993.
Federal judicial service
On the recommendation of SenatorsTed Kennedy and John Kerry, Saris was nominated as a United States District Judge of the United States District Court for the District of Massachusetts by President Bill Clinton on October 27, 1993, to a seat vacated by Walter Jay Skinner. She was confirmed by the United States Senate on November 20, 1993, and received her commission on November 24, 1993. She served as Chief Judge from January 1, 2013, until December 31, 2019.[4] On November 20, 2023, she announced her intention to assume senior status upon confirmation of a successor.[5]
In 2008, Saris sat by designation with the United States Court of Appeals for the First Circuit in the case of Cook v. Gates,[6] which upheld the "Don't ask, Don't tell" (DADT) policy (Title 10, Section 654) against due process and equal protection Fifth Amendment challenges and a free speech challenge under the First Amendment, and which found that no earlier Supreme Court decision held that sexual orientation is a suspect or quasi-suspect classification.[7] Saris concurred with the majority regarding due process and equal protection, while dissenting with the rejection of the First Amendment challenge, because "if the Act were applied to punish statements about one's status as a homosexual, it would constitute a content-based speech restriction subject to strict scrutiny" and that "the availability of an administrative remedy does not defeat a First Amendment claim that the government is systematically applying the Act in such a way that it unconstitutionally burdens protected speech".[8]
United States Sentencing Commission
In April 2010, President Obama nominated Saris as Commissioner and Chair of the United States Sentencing Commission. She was confirmed by the Senate on December 22, 2010[9][10] and sworn in by Justice Elena Kagan on February 16, 2011.[11] Her term expired on January 3, 2017.