Kingston police received a 911 call just after 11 a.m. on Sunday for a home on Elm Street, where they found a man and woman, both 45, shot to death inside, Plymouth District Attorney Tim Cruz told WCVB. Officials have not released their names and did not say which was the aggressor.
The couple had a young daughter, but it's unclear if she was home during the killing.
Massachusetts State Police is investigating the slaying with the Kingston Police Department.
Neighbor Sally Phillips told NBC Boston she met the family earlier this year, and they seemed nice.
"He was so proud of his home and his family, and it just seems so out of character," she said.
Click here to follow Daily Voice Cambridge and receive free news updates.