(CNN) Nearly a year after the execution-style slayings of eight family members stunned a rural southern Ohio community, the mystery surrounding the massacre remains unsolved.

At a press conference on Thursday, state and local authorities said they were "getting closer" to cracking the case, but do not have "enough to announce any arrests. "

"You want answers ... we just can't give now," Pike County Sheriff Charles Reader said.

But Ohio State Attorney General Mike DeWine said he was "confident" the puzzle surrounding the Rhoden family killings would be solved. He encouraged those with information to come forward.

"It remains the top priority of the attorney general's office," he said.

The eight victims -- who ranged in age from 16 to 44 -- were found shot to death at four crime scenes around the small town of Piketon in April last year.

Slayings sent 'shockwave' round community

Dana Rhoden

DeWine said the attorney general's office would maintain a presence in Piketon "until this case is solved." At least a dozen of his agents are in the community -- a town of about 2,000 residents, 90 miles east of Cincinnati -- he said.

Sheriff Reader choked back tears when talking about the "shockwave" the murder had sent around the community. He said his heart hurts most for the friends and relatives of the Rhoden's.

At one of four crime scenes, police found a 4-day-old baby lying next to his mother, who was one of the victims. That child, along with a 6-month-old and a 3-year-old, survived the killings.

"There are babies that will grow up without their mothers or grandparents.

They've missed birthday's or anniversaries," Sheriff Reader said. "I think about them on Thanksgiving or Christmas and think about what they're going through."

Authorities also announced a $10,000 Crime Stoppers reward for information leading to arrests in the case. A billboard with the faces of the victims was put up locally on Thursday.

Authorities have received nearly 900 tips

Frankie Rhoden

Dewine said investigators have received 883 tips, conducted 465 interviews -- with some people interviewed multiple times -- and carried out 38 search warrants.

They have also completed 60 "cyber extractions," which DeWine said included scouring cell phones and DVR's for any evidence in the case.

The murders were described by the local sheriff has the "most brutal homicides" he'd ever investigated. On Friday, April 22, 2016, authorities received a 911 call at about 7:53 a.m. informing them that two bodies had been found. Officers later were told other bodies had been located.

Investigators at first found seven victims at three residences in the county, two "within walking distance" and the third about a half a mile away," Sheriff Reader said at the time. Hours later, an eighth body was located in a fourth residence about 8 miles away.

'Somebody knew what they were doing'

Hanna May Rhoden

The victims were 44-year-old Kenneth Rhoden, his brother Christopher Rhoden Sr., 40, and Christopher's ex-wife Dana Rhoden, 37. Three of the Rhoden's children, Clarence "Frankie" Rhoden, 20, Christopher Rhoden Jr., 16, and Hanna May Rhoden, 19, also were killed. The last two victims were Hannah Gilley, 20, who was engaged to Clarence "Frankie" Rhoden, and Gary Rhoden, 38, a cousin.

"These were fairly remote areas, somebody knew what they were doing," Attorney General DeWine said at Thursday's press conference.

Until now, authorities have refused to release the details about their investigation. DeWine has said he believes it was more than one killer.

"I feel that they are local to the area," Sheriff Reader added.

Marijuana growing operations uncovered

Authorities in Ohio released this chart tracing the relationships of the Rhoden family members.

A few days after the killings, Sheriff Reader and DeWine held a press conference during which they said a commercial grade "marijuana grow operation" had been discovered at two of the crime scenes.

At one of the crime scenes, investigators said, money had been thrown on top of the bodies. It also appeared that, at one of the locations, the killer or killers had attempted to clean up after themselves, authorities said.

The report of the marijuana growing operation led many in the small community to speculate that the killers could have been involved in drugs or drug dealing in some way -- have been tied to Mexican drug cartels. The cartels, in years past, have used the rural and mountainous Pike County to grow marijuana, authorities say.

Investigators maintain that they believe the family was targeted.

"We are not at the point of diminishing returns," DeWine said at Thursday's news conference.

"We will find you. We will arrest you."