Authorities say they found marijuana-growing operations at three of the four locations where eight family members in rural southern Ohio were found fatally shot.

They said at a news conference Sunday that it’s unclear what, if any, role the growing operations had in Friday’s killings. Seven adults and a teenage boy, all Rhoden family members, were found shot in the head at homes near Piketon.

Attorney General Mike DeWine called the slayings a “pre-planned execution.”

DeWine and Pike County Sheriff Charles Reader would not comment on a possible motive, but said the investigation will be lengthy. More than 100 personnel are assisting in the investigation.

Autopsies on the bodies are expected to be completed Monday.

DeWine said that the attorney general’s office doesn’t know if there is one or more suspects. DeWine called the killings a “sophisticated operation.”

Authorities earlier identified the eight family members who were fatally shot in the head. Authorities on Saturday identified them as 40-year-old Christopher Rhoden Sr.; his 16-year-old son, Christopher Rhoden Jr.; 44-year-old Kenneth Rhoden; 38-year-old Gary Rhoden; 37-year-old Dana Rhoden; 20-year-old Clarence “Frankie” Rhoden; 20-year-old Hannah Gilley; and 19-year-old Hanna Rhoden.

A cook at a local restaurant said many people in the community remain on edge after the slayings.

Maggie Owens said her son was friends with one of the victims, 16-year-old Christopher Rhoden Jr. Owens says she also knew 37-year-old Dana Rhoden, who she described in a phone interview on Sunday as having “a heart of gold.”

The victims’ bodies are at the Hamilton County coroner’s office, where autopsies are expected to take the weekend.

Del Greco says investigators want to keep the scenes preserved in case they need to review them again.

Gov. John Kasich is calling the slaying of eight family members in rural southern Ohio “a horrible set of murders.”

Kasich said he’s been getting updates on the case as he is campaigning out of state for the Republican presidential nomination.

The governor told CBS in an interview Saturday that he is confident the perpetrators would be found and “justice will be delivered to them.”

Kayla Hay said she’s a former co-worker of one of the victims. She said she never heard Dana Rhoden say anything about being frightened or concerned about anything bad happening.

Outdoors shop owner Todd Beekman said at least one customer has come in to stock up on ammunition after hearing about the shootings.

Investigators said they’ve questioned more than 30 people.