The 1978 cold case murder of California high school teacher Diane Peterson, who was stabbed to death, has been solved this year, officials confirmed.

Two people from the northwestern North Dakota town of Stanley are in custody in connection with the March death of a 3-year-old girl.

All three died of a gunshot wound to the head, Swanson said, and while still under investigation Swanson said the incident appears to have been a murder-suicide.

Valparaiso police had posted on social media Monday night that officers were on scene in the 1900 block of Chicago Street with a criminal investigation.