The state attorney general's office says 54-year-old David Caplin was turned over by Canadian authorities to the U.S. Marshal's Service on Tuesday. He was then arrested by police in Nashua, N.H..
Caplin's return to the U.S. follows a lengthy legal fight that ended last month when the Supreme Court of Canada ordered his extradition, along with the extradition of his co-accused, Anthony Barnaby.
Caplin and Barnaby are Canadian Micmac Indians who were working construction in Nashua when 48-year-old Charlene Ranstrom and 32-year-old Brenda Warner were bound, beaten and stabbed to death in their home in October 1988.
Barnaby was tried three times in the killings, but each trial ended in a hung jury and charges were dismissed after the third mistrial in 1990. Caplin was charged, but never tried after key evidence was excluded.
The case languished for two decades, but was re-opened in 2010, when police re-interviewed witnesses and new DNA testing techniques were used.
The Canadian government ordered Caplin and Barnaby's removal in 2011, but their cases were under appeal.
U.S. prosecutors say they can't comment on when Barnaby can be expected in New Hampshire.