Eight members of the same family were executed in a remote area of southern Ohio one night six years ago, and four members of another family were charged for the shocking slayings that stunned the country.
After numerous delays, George Wagner IV, 30, is the first defendant in the case to go to trial, which began last week in Pike County Court with the seating of 12 jurors.
Opening statements were scheduled for Sept. 6, but an illness of a participant in the case delayed the proceeding by a week, court records show.
After seven adults and one teenager were found shot to death at three trailers and a camper on April 22, 2016, authorities launched what became the largest criminal investigation in Ohio’s history.
RHODEN FAMILY EXECUTION-STYLE MURDERS: 4 FAMILY MEMBERS ARRESTED IN 2016 OHIO KILLINGS
Rumors initially swirled that a Mexican cartel may have been responsible due to two family members' alleged role in a marijuana-growing operation.
But the probe ultimately led to the arrest of George Wagner IV, his brother, Edward "Jake" Wagner, their mother Angela Wagner and their father George "Billy" Wagner III.
"There certainly was obsession with custody, obsession with control of children," then-Ohio Attorney General Mike DeWine said at a press conference announcing the arrests. "This is just the most bizarre story I've ever seen in being involved in law enforcement."
Officials said the Wagners spent months planning the killings and were motivated by a custody fight between Jake Wagner and a child he had with victim Hanna Rhoden.
The feud between the families has been described as a modern-day Hatfield and McCoy rivalry.
The jury, primarily composed of women, began its service last week with a haunting trip to the site of the mass murder at the foothills of the Appalachian Mountains.
The victims were Christopher Rhoden, Sr., 40, his ex-wife Dana Manley Rhoden, 37, and their three children: Hanna Rhoden, 19, Christopher Rhoden Jr., 16, and Clarence "Frankie" Rhode, 20.
Frankie Rhoden's fiancée, Hannah "Hazel" Gilley, 20, was also killed, along with the elder Christopher Rhoden's brother Kenneth Rhoden, 44, and cousin Gary Rhoden, 38.
Prosecutors say that Jake, the younger George and the elder George Wagner methodically ambushed the Rhodens, storming each of their trailers in the dead of night.
They used guns with homemade silencers and "phone jammers" to prevent the victims from calling for help, according to prosecutors.
Most of the victims were repeatedly shot in the head as they slept. The killers spared two infants and a toddler who were later found splattered with their parent’s blood.
Some of the victims were collateral damage, "killed because they happened to be there," according to special prosecutor Angela Canepa.
The area is one of the poorest in Ohio and has been hit hard by the opioid epidemic.
Prosecutors say Jake Wagner began dating Hanna Rhoden when she was 13, and conceived a child with her two years later when he was 20, according to prosecutors.
The couple split, and a vicious fight over custody of their daughter soon erupted. Rhoden refused to sign papers agreeing to share custody with George Wagner IV.
RHODEN FAMILY MURDERS HAVE LINK TO CUSTODY DISPUTE, OHIO AG SAYS
"They will have to kill me first," she wrote in a message on Facebook in December 2015.
Unbeknownst to her, the Wagners had seen the message after Angela Wagner allegedly hacked into her Facebook account.
Rhoden had also become pregnant with another man’s child, and Jake Wagner didn’t want their daughter exposed to her new boyfriend or his family, according to prosecutors.
The Wagners allegedly began plotting Rhoden’s demise and anyone else in her family that they felt stood in the way of custody.
The Wagners operated as one unit, making family decisions by putting them to a vote, even discussing when George and Jake Wagner should be intimate with their wives, Law & Crime reported.
They lived an insular life, homeschooling their children and working together as truckers.
FLASHBACK: TIPS SOUGHT ON 4 PEOPLE, INCLUDING VICTIM'S EX, IN RHODEN FAMILY KILLINGS
Rhoden wasn’t the first ex allegedly targeted by the Wagners.
Tabitha Claytor, George Wagner IV's ex-wife with whom he shares a son, told investigators she signed court papers under pressure from the family giving up custody with a promise that the arrangement was temporary.
But the Wagners allegedly wouldn't let her see him.
George "Billy" Wagner III has pleaded not guilty and is set to go to trial after his son.
In a surprise move, Jake Wagner pleaded guilty last year to multiple counts of murder and other charges on the fifth anniversary of the executions.
The 29-year-old confessed to killing five of the victims in a plea deal that will spare him the death penalty if he testifies against his brother and father.
He said in court he was "deeply and very sorry" for what he'd done, and his lawyer added that Wagner understood that he would spend the rest of his life behind bars.
OHIO 'PIKE COUNTY MASSACRE' SUSPECT PLEADS GUILTY TO 8 MURDERS OF EX, HER FAMILY
"He knows he's going to die in prison without any judicial release. As horrifying as this is for all, he is as sorry as he could be," defense attorney Gregory Meyers told a judge during the plea.
After her son turned on the family, Angela Wagner soon followed, giving prosecutors new information and asking for a deal.
She pleaded guilty to helping plan the murder — which she was not present for — and agreed to testify against her husband and son in exchange for a recommended prison term of 30 years.
George Wagner IV's defense lawyers have argued that he only went along with the slaughter that night out of fear his father would kill Jake Wagner if he didn't, according to court papers.
They also said he was not directly responsible for a single murder.
"George did not shoot or kill anybody that's a named victim in this case," attorney John Parker told the judge during a prior hearing. "He did not pull the trigger once."
But prosecutors contend that the four defendants conspired to commit the murders, making all parties guilty under Ohio law, regardless of who pulled the trigger.
The trial is expected to last six to eight weeks, and more than 250 witness could be called.
The Associated Press contributed to this report.
