GREENFIELD, Mass. (AP) — Authorities have released the names of a Greenfield couple who were found dead in their home Wednesday, but how they died remains a mystery.

The Northwestern district attorney's office identified the couple on Thursday as 53-year-old Margaret Pekkala and 54-year-old Dennis Pekkala. The prosecutor's office says medical examiners are still investigating the causes of their deaths.

Local police told The Recorder of Greenfield that there were no obvious signs of how the couple died, including no signs of a struggle, forced entry or drug overdoses. Police also say they don't believe carbon monoxide played a role.

Their roommate found them unresponsive in their bedroom shortly after 6 a.m. Wednesday.

Authorities added they don't believe there is any danger to the public.