(CNN) -- Ohio prosecutors are asking that a teenager be tried as an adult in the killings of three men and the wounding of a fourth, each of whom answered a Craigslist ad for work on a cattle farm, officials said Tuesday.
Brogan Rafferty, 16, and Richard Beasley, 52, face multiple charges in the case.
An Ohio grand jury Friday indicted Beasley, alleging that he pulled the trigger. His arraignment is scheduled for Wednesday, said April Wiesner, director of communications for the Summit County prosecutor's office.
Rafferty, of Stow, Ohio, had a preliminary hearing Monday at which prosecutors filed a motion asking he be tried as an adult, Wiesner said. A probable cause hearing on whether to bind him over to adult court has not been set, she said.
The high school sophomore is charged with three counts of aggravated murder, one count of attempted murder, and robbery and kidnapping, according to Wiesner.
Rafferty has entered a not guilty plea.
His father, Michael, told CNN Cleveland affiliate WJW in late November that his son had been "manipulated" and "corrupted," insisting that the teenager is a "mild-mannered gentleman."
The father also said that his son unwittingly dug the graves at Beasley's direction, WJW reported. The boy's mother said her son denied killing anyone and added that Beasley portrayed himself as "a chaplain" who gave food to the homeless.
Beasley faces multiple counts of aggravated murder, kidnapping and aggravated robbery as well as a host of other charges, according to the 28-page indictment released Friday.
Ralph Geiger, 56, of Akron, Ohio; David Pauley, 51, of Norfolk, Virginia; and Timothy Kern, 47, of Massillon, Ohio; were found dead in separate shallow graves after they responded to an online ad soliciting workers between August and November of last year, authorities have said.
Ohio Attorney General Mike DeWine acknowledged last week there may be more victims, and thus more charges.
"We are dealing with serial killings here," DeWine told reporters, pleading for the public to provide more information. "Are there more bodies? Frankly, we don't know. If there are, we need to find them."
The indictment calls Beasley the "principal offender" in the killings, Summit County Prosecutor Sherri Bevan Walsh said.
He could be eligible for the death penalty if he is convicted, because the killings appear to meet one or more requirements for that sentence, including purposely causing the death of two or more people and murdering people while a fugitive, committing a kidnapping and/or committing armed robbery.
"This case deserves the death penalty for a multitude of reasons," Walsh said. "This case, we view to be one of the worst of the worst when it comes to horrible murder cases."
The investigation into the killings began the night of November 6, when a Noble County deputy sheriff responded to a call and came upon a "white, middle-aged man being treated for a gunshot wound to the right arm," according to Sheriff Stephen S. Hannum of Noble County.
The wounded man -- who was identified in the indictment as Scott Davis, 48, from South Carolina -- told the law enforcement officer that he had answered an ad on the Craigslist website offering work caring for cattle on a 688-acre property in eastern Ohio.
He met with two males, including Beasley, and drove with them toward Stock Township, Ohio. After being told a road was closed due to a landslide, Davis got out of the car to start walking toward the property, which he was told was nearby.
Davis told the sheriff that, while walking through a heavily wooded area, he turned around "to see a gun pointed at his head. He deflected the gun and ran" -- getting shot in the arm while fleeing, the sheriff explained late last year. The victim hid for seven hours in the forest before going to a house and requesting help, Hannum said
The third victim, Kern, was killed one week after Davis' escape, according to authorities.
The attorney general said that the victims were all "down on their luck" men trying to take advantage of an opportunity to "have a better life."
One of the shooting victims was found in Summit County and the others in Noble County. The attorney general's office and local jurisdictions decided to consolidate the cases in Summit County.
CNN's John Fricke and Rich Porter contributed to this report.