(NewsNation) — Several new details have emerged about the killings of two Kansas mothers whose suspected killers had a violent history of plotting to kill and went to extreme lengths to conceal the crime, according to new court documents that reveal why the defendants were denied bail.

Tifany Adams, 54; her boyfriend Tad Cullum, 43; Cora Twombly, 44; and her husband Cole Twombly, 50, have each been charged with two counts of first-degree murder, two counts of kidnapping and one count of conspiracy to commit murder in the first degree, of Veronica Butler, 27, and Jilian Kelley, 39.

A source close to the investigation told NewsNation’s “Banfield” that Butler, the mother of Adams’ grandchildren, fiercely fought back against her attacker while still inside the car before being killed.

Her alleged assailant, Cullum, was found with crescent-moon-shaped scratches on his face resembling fingernail marks when arrested. The source said Cullum grew his beard longer in an attempt to cover up the scratches after previously keeping it well-trimmed.

The suspects arrested were officially arraigned in an Oklahoma court Wednesday, when a judge denied each of them bond. The quartet, allegedly part of an anti-government religious group called “God’s Misfits,” have become central figures in the investigation.

New court documents

Adams admitted responsibility for Butler and Kelley’s deaths, according to court documents obtained by NewsNation.

In the motions to hold the four defendants without bail, records state, in part, that Adams “did provide a recorded statement to law enforcement indicating her responsibility for the death of the deceased.”

The document also alleges that Adams and Cullum “have a history of violent interactions including death threats and intimidation … abide by their own philosophy and have no regard for the sanctity of human life.”

This aligns with rumors that the couple was feared in the community for their mean streak and perceived dangerousness.

When arrested, Cullum allegedly had a rifle, ammunition, body armor and a “go-bag” at his residence.

According to the documents, Adams and Cullum plotted to kill Butler previously by “dropping an anvil through her windshield.”

Prosecutors cited this alleged propensity for violence, along with evidence the pair were well-resourced and prepared for potential flight, in their bid to hold them without bail — a request the judge granted.

Of particular concern were statements by the suspects that they “knew the path the judge walked to work” in a previous custody case involving Butler’s children, raising fears they could try to intimidate the court.

The judge entered not-guilty pleas for all four defendants, with the possibility of capital punishment still on the table. In Oklahoma, the maximum sentence for murder is death, life or life without parole.

“Now faced with the consequences of a sentence of death or life in prison, the defendants would be willing to do anything since they have shown to be willing to commit capital murder in order to limit Veronica’s visitation,” court documents state.

Bodies found 10 feet below ground

Cullum allegedly dug a 10-foot grave on property owner Jamie Beasley‘s land near a dam and pond, claiming he just needed to “do some dirt work” and bury concrete, according to the landlord.

Two days before the women disappeared, Cullum asked Beasley if he could use a skid-steer to remove a stump and dig on the property. Beasley agreed.

After the women went missing, Cullum warned Beasley that police considered him a suspect and that the skid-steer tracks “might look suspicious.” Beasley said he would simply confirm Cullum had been doing dirt work if asked.

NewsNation visited the site at night and documented the disturbed earth about 50 feet from the dam where authorities eventually found the bodies buried 10 feet underground.

There was a hay bale nearby that sources said Cullum had strategically positioned to attract cattle and obscure evidence of the digging.

The property, which is located 8 1/2 miles from the location where the women disappeared and where Butler’s vehicle was found, had fresh dirt work done, and discarded burner phones were found.

“The area of disturbed dirt was excavated, and the bodies of two individuals were discovered,” court records state.