The suspects accused of killing two Kansas mothers who went missing in Oklahoma allegedly had previously planned to kill one of the women with an anvil, court documents obtained by HNGN have revealed. 

The suspected bodies of Veronica Butler, 27, and Jilian Kelley, 39, were found over the weekend.

They disappeared on their way to pick up Butler's children for a court-ordered visitation.

Police arrested 54-year-old Tifany Adams, who was the children's grandmother, 43-year-old Tad Bert Cullum, 50-year-old Cole Earl Twombly and 44-year-old Cora Twombly on murder, kidnapping and conspiracy charges.

A teenaged witness in the case told investigators that in February the four had traveled to Hugoton, Kansas in a previous attempt to kill her.

They allegedly planned to throw an anvil through Bulter's windshield while driving. They reportedly thought it would look like an accident because anvils "regularly fall off of work vehicles," according to Adams' arrest affidavit obtained by HNGN. 

The group allegedly called off the plan when they couldn't lure Butler out of the house.

Authorities say a search of Adam's phone showed searches for "how to get someone out of their house."  Other searches reportedly were for taser pain level, gun shops, and prepaid cellular phones.

The witness aid that Adams had provided "burner" phones for the group to use so they could communicate without using their personal devices.

The four were members of an anti-government group with a religious affiliation called "God's Misfits," according to their arrest affidavits. They reportedly held weekly meetings at the Twombly's home and another home.

Authorities in Oklahoma say they have located the bodies believed to be two women who went missing in rural Oklahoma and are believed to have been murdered.

The Oklahoma State Bureau of Investigation said the bodies believed to be of Butler and Kelly were found in Texas County and the medical examiner's office to make an official identity.

Their vehicle was found abandoned near Highway 95 in Texas County and the Oklahoma State Bureau of Investigation said there was evidence to indicate foul play.

They had arranged with the grandmother of Butler's two children to meet at a highway intersection and pick up the 6- and 8-year-old on March 30. The children were supposed to attend a birthday party.

Butler was in a long-running custody battle with Adams. Her son, the father of Butler's two children, was in a rehabilitation facility in Oklahoma City.

Butler was allowed supervised visits with the children each Saturday.

Kelley, the wife of a pastor, was Butler's court-authorized choice to supervise visitations.

The teenage witness told authorities that Cora Twombly said that she and her husband blocked the road to stop Butler and Kelley and divert them to where Adams, her boyfriend Cullum and another person were waiting for them.

The teen reportedly asked why Kelley had to die and was told that "she wasn't innocent either" because she supported Butler," the court papers said.