In 1980, Thompson became the Assistant City Solicitor for Providence, Rhode Island, and held this position until 1982.
[3] Also in 1980, Thompson was a solo practitioner until 1984 when she opened a law firm in South Providence while raising a family with her husband, Rhode Island District Court judge William Clifton.
[1][2] On April 13, 2009, United States Senators Jack Reed and Sheldon Whitehouse announced that they were recommending that President Obama nominate Thompson to the United States Court of Appeals for the First Circuit, to fill the seat left vacant by First Circuit Judge Bruce M. Selya's transition to senior status at the end of 2006.
[2] In August 2017, Thompson dissented when the en banc circuit rejected a lawsuit seeking to give Puerto Ricans the right to vote in U.S. federal elections.
[7][8] In July 2020 Thompson was part of an appellate court decision that vacated the death sentence and overturned three of the firearm convictions of Boston Marathon bomber Dzhokhar Tsarnaev, and referred the matter back to the lower courts.