The four suspects charged with murdering two Kansas women in Oklahoma were denied bond Wednesday, as prosecutors alleged one of them provided a statement "indicating her responsibility" in the killings, court records show.

Tifany Adams, 54, her boyfriend Tad Cullum, 43, Cole Twombly, 50, and Cora Twombly, 44, are each charged with two counts of first-degree murder, kidnapping and conspiracy to commit murder. 

The judge entered not guilty pleas for all four, who are accused of killing Veronica Butler, 27, and Jilian Kelley, 39. The two Kansas women disappeared March 30 while on their way to pick up Butler's children from a birthday party in nearby Oklahoma.

According to a motion to deny bail to the four suspects, prosecutors claim that, after Adams was arrested, she "did provide a recorded statement to law enforcement indicating her responsibility for the death of the deceased."  

"Adams, Cullum, Cora and Cole have resources sufficient to organize and execute a complex murder," an affidavit stated. "Therefore, they also have the resources to flee if given the opportunity."   

Family members of the deceased were at the courthouse Wednesday to confront Butler and Kelley's alleged killers. 

Bryson Butler, Veronica Butler's younger brother, told CBS affiliate KFDA, "just hope justice is served."

"How can you hate somebody so much that you want to kill them? How can you hate the mother of your grandchildren so much that you want to end her life?" Butler's aunt told KFDA. 

Adams is the paternal grandmother of Butler's children, and the two had been in a custody dispute before Butler's death. At the time of her disappearance, Butler was only allowed supervised visits with her children on Saturdays, and Kelley was the supervisor that day, according to an affidavit.

The car the two women had been traveling in was found on the side of the road in late March, and evidence, including blood and a broken hammer found nearby led authorities to believe they disappeared as a result of "foul play."

Butler and Kelley remained missing for two weeks until their bodies were found on April 14, one day after the four suspects were arrested. According to an affidavit, their bodies were found on property that was leased by Cullum, and a stun gun was also found at the site.

Authorities claim data from Adams' phone showed that she searched for "taser pain level, gun shops, prepaid cellular phones and how to get someone out of their house," according to the affidavit. 

According to authorities, all four suspects belong to an anti-government group called "God's Misfits" that met weekly at the Twomblys' home and other locations. The group had allegedly tried to kill Butler before, including by attempting to lure her out of her home in Kansas, according to a teenage witness who spoke to investigators.

Authorities believe Adams allegedly killed Butler because there was a possibility she would have been granted unsupervised visits with her children during a hearing that had been scheduled for April 17. 

"Adams vehemently opposed this and went to great lengths to plan and purchase items used in Butler and Kelley's murder," an affidavit stated.

Jordan Freiman

Jordan Freiman is an editor and writer for CBSNews.com. He covers breaking news, trending stories, sports and crime. Jordan has previously worked at Spin and Death and Taxes.