Jilian Kelley and Veronica Butler
CNN  — 

The bodies of two women who were slain in rural Oklahoma last month were buried in a cattle pasture leased by one of the four suspects – all of whom are accused of plotting the victims’ deaths amid a bitter custody battle, according to court documents.

The location of the bodies of Veronica Butler, 27, and Jilian Kelley, 39, is among several new details included in court filings by prosecutors arguing that the suspects should be denied bail – a request that was granted by a judge Wednesday.

The suspects – Tifany Machel Adams, 54, Tad Bert Cullum, 43, and married couple Cole Earl Twombly, 50, and Cora Gayle Twombly, 44 – each face murder, kidnapping and conspiracy charges after the two women went missing on a drive between Kansas and Oklahoma and were later found dead, according to authorities.

All four suspects were assigned court-appointed attorneys with the Oklahoma Indigent Defense System, and the agency’s policy is not to speak to the press regarding pending cases, according to Charles Laughlin, the agency’s executive director.

The documents allege Adams and her significant other, Cullum, engaged in a killing plot with the Twomblys that was motivated by a custody battle between Butler and Adams, who is the grandmother of Butler’s two children. The group is also accused of unsuccessfully attempting to kill Butler in February, the documents state.

Adams allegedly gave statements to investigators after her arrest “indicating she was responsible for the deaths of Butler and Kelley,” according to the affidavit.

The custody arrangement, which required Butler’s visitation with her children every Saturday to be supervised, was potentially about to take a turn in Butler’s favor as her attorney informed investigators she was likely to get unsupervised visitation during an upcoming hearing, according to the affidavit.

“Adams vehemently opposed this and went to great lengths to plan and purchase items used in Butler and Kelley’s murders,” the affidavit stated. “Adams, Cullum, Cole and Cora were willing to kidnap and murder two victims to limit visitation for Butler.”

(Clockwise from top left) Cole Earl Twombly, Cora Twombly, Tifany Machel Adams and Tad Bert Cullum have been charged with murder, kidnapping and conspiracy.

Butler and Kelley went missing on March 30 as they were driving together from Hugoton, Kansas, to Four Corners, Oklahoma, for Butler’s supervised visit with her children, according to the affidavit.

Their vehicle was found abandoned near a highway in Texas County, where investigators found a bloody scene scattered with “evidence of a severe injury,” probable cause documents state.

Investigators determined Adams purchased three burner phones – all of which had pinged near where Butler’s car was found and at the last known location of the women before their disappearance, according to the affidavit.

Cell phone data from two of the burner phones led authorities to a pasture property rented by Cullum, where a hole had been dug and filled back in, the affidavit states.

The disturbed dirt was excavated and two bodies – later identified as Butler and Kelley – were discovered, the affidavit said. The site was about 8.5 miles from where the abandoned car was found, it noted.

“The state of the bodies indicated they died as a result of foul play,” the affidavits stated. No further details about the condition of the bodies were provided.

A stun gun was also found near the site, according to the affidavit.

In their arguments to deny the suspects bail, prosecutors said the killings were “complex and involved extensive preparation,” according to the court motion. Prosecutors also noted that some of the suspects had “resources to flee if given the opportunity” and “pose grave danger to witnesses community members.”

Outside court on Wednesday, Butler’s younger siblings held back tears as they described the “beautiful soul” that was taken from them too soon.

“She’s just like a sunflower, just like a beautiful sunflower looking in the sun,” said Junia Butler, Veronica Butler’s younger sister, to CNN affiliate KFDA. “She’s amazing, an amazing mom.”

Investigators say they found evidence of ‘severe injury’

Butler’s visitation with her two children every Saturday had to be supervised, and Butler planned to have Kelley supervise the visit, according to the probable cause documents.

On March 30, Butler and Kelley were scheduled to pick up the children from Adams at about 10 a.m. and attend a birthday party, but they never made it to the event, according to the documents.

Butler’s family then located her abandoned vehicle in a rural area of Texas County and called police, the documents show.

“An examination of the vehicle and area surrounding the vehicle found evidence of a severe injury. Blood was found on the roadway and edge of the roadway. Butler’s glasses were found in the roadway south of the vehicle, near a broken hammer. A pistol magazine was found inside Kelley’s purse at the scene, but no pistol was found,” the probable cause documents state.

Butler’s and Kelley’s phones were actively sending signals to their carriers until about 9:42 a.m. and then stopped transmitting, the probable cause documents state. The phones have not been recovered, according to the documents.

State investigators extracted information from Adams’ phone that showed web searches for “taser pain level, gun shops, prepaid cellular phones and how to get someone out of their house,” the probable cause documents show. Adams also purchased five stun guns in the months and days leading to the women’s disappearances, according to the documents.

All four defendants are described as being part of “an anti-government group that had a religious affiliation,” according to statements made to investigators by Cora Gayle Twombly’s teenage daughter and recorded in the probable cause documents. The Oklahoma State Bureau of Investigation later learned the group went by the name “God’s Misfits” and they met weekly, sometimes at the Twomblys’ residence, the probable cause documents state.

The FBI Oklahoma City field office said it is assisting in the investigation with a “dedicated team of agents, analysts, task force officers, evidence response personnel and tactical” teams.

CNN’s Andy Rose contributed to this report.

Correction: An earlier version of this story incorrectly spelled the name of Veronica Butler’s younger sister, Junia Butler.