"They've had such an on-and-off again, bad relationship," Brandi Koechner said. "He knew how to get into her head. All of us were really scared because we've seen what he can do."
Sandner, of Brookfield, was charged in January in Livingston County with third-degree domestic assault after his new girlfriend told police he had struck her in the face at a Chillicothe motel. He pleaded guilty in 2007 to third-degree domestic assault involving a different woman and was given a 60-day suspended sentence.
Hughes said Sandner isn't expected to be charged in connection with Koechner's disappearance, but was being held Tuesday in Chariton County Jail on five forgery charges from a Linn County case. Prosecutors allege he wrote five bad checks on the account of another man last August.
Koechner hadn't been charged by midday Tuesday, but was being held without bond in the Chariton County Jail pending charges. Hughes expected her to at least be charged with making a false report.
Neither Sandner nor Koechner had acquired an attorney, and Hughes declined an Associated Press reporter's request to interview either of them at the jail.
Media coverage Monday of what was then being described as a possible abduction forced Koechner, Sandner and their daughter to leave the motel in the Kansas City suburb of Blue Springs early, even though they had paid for another night in advance, the sheriff said.
"He said, 'I saw my picture on the news yesterday morning and I started freaking out,'" Hughes said of Sandner.
Rachel Koechner called her boyfriend around 9 a.m. Monday to tell him she was OK and to have the search called off. The boyfriend, whose name has not been released, told Hughes the conversation sounded scripted.
Hughes tracked the phone number to the Blue Springs motel, which he called just as Koechner, Sandner and their daughter were checking out. The motel worker who answered the phone handed it to Koechner.
"She said she couldn't talk now," Hughes said. "I asked if she was OK, and she said, 'No.'"
The sheriff contacted Blue Springs police, but the three were gone by the time officers arrived at the motel.