A shooting that left four people dead inside a Madbury, New Hampshire, home earlier this week has been ruled a murder-suicide.

Investigators have released the identities of four family members, including two children, who were found dead at a Seacoast home Monday night, authorities said.

“Each of the deceased family members appears to have suffered gunshot wounds, and were pronounced dead at the scene,” New Hampshire Attorney General John M. Formella’s office said, in a joint statemen...