One of the four people arrested Saturday on suspicion of murder and kidnapping in the May 30 disappearance of two Kansas moms was in a custody battle with one of the victims, authorities said in an arrest affidavit obtained by HuffPost. Their bodies were found Sunday.

Authorities on Monday confirmed the deaths of Veronica Butler, 27, and Jilian Kelley, 39, who disappeared on their way to pick up Butlers 6-year-old daughter and 8-year-old son from their paternal grandmother, Tifany Machel Adams, 54, for a birthday party, authorities said. Butler never showed up, and relatives later found her abandoned car by a desolate stretch of highway across the border in Oklahoma and called the police.

Adams; her boyfriend, Tad Bert Cullum, 43; and married couple Cole Earl Twombly, 50, and Cora Twombly, 44, were arrested Saturday on suspicion of murder, kidnapping and conspiracy in connection to Butlers and Kelleys disappearance.