A Texas man is behind bars after investigators say he killed his girlfriend, then drove across state lines to dump her body, according to new details revealed in an arrest affidavit.

Authorities allege Christopher Charles Sanders, 53, murdered 31-year-old Molly Richards in late November 2025 after the couple traveled from Texas to South Dakota. Her remains have not been found.

Despite not having located her body, investigators say evidence has led them to believe Richards was murdered. On March 7, police arrested Sanders in Marietta, Oklahoma, as he was traveling from South Dakota. Sanders denied killing Richards and wouldn’t provide any details on her whereabouts.

An investigation was first launched in January by police in Little Elm, Texas, after Richards’ father, Steven Richards, contacted them after not hearing from his daughter since November.

According to the affidavit obtained by WFAA, Richards last saw his daughter in November 2025. She later texted him saying she and Sanders were traveling to South Dakota.

The worried father told investigators that his daughter had recently moved in with Sanders at a home in Little Elm in October and that she had previously told him about alleged abuse.

On December 1, he received what would be the final message from her, stating she was checking herself into a mental health facility for bipolar disorder. After that, his messages went unanswered.

“Went by your place. Where is Molly anyway?” Richards said in a text to Sanders on December 10. “There was no answer at the door, and I didn’t see her car. I am worried about Molly. Can you tell me where she is and how she is doing?”

But Sanders did not respond, prompting Richards to contact police and file a missing persons report.

During the investigation, authorities traced Molly Richards’ car to Deadwood, South Dakota, where it had been involved in a minor crash. A witness there told police he had met the couple at a bar in November and had agreed to watch her car at Sanders’ request, according to the affidavit.

The witness said Sanders claimed he was taking Richards to see a doctor in Rapid City, then flew back to Texas, later returning to retrieve his own vehicle while leaving hers behind. The witness also said that Sanders had claimed that Richards had met another man and was staying behind with him at a motel in Rapid City.

Mental health facilities, hospitals and motels were contacted, but investigators found no record of Richards ever checking in to any of the places as claimed by Sanders.

Days later, a woman caring for Sanders’ dogs at his South Dakota property discovered several of Richards’ belongings in a dresser drawer, including her driver’s license, bank cards, laptop, prescription medication, and unopened mail, according to the affidavit.

Her laptop had not been used since November 14, and her bank accounts had no activity beyond recurring subscription charges after November. Investigators noted that, based on prior interactions with Richards, it would be out of character for her to leave behind her ID and other personal items.

Search warrants were executed at properties tied to Sanders in Little Elm and Denton and investigators reported finding bedding with blood residue and a receipt for items including a 24-inch bow saw, multiple five-gallon buckets, a tamper, a reciprocating saw, and gloves, according to the affidavit. The tools were not recovered.

Authorities allege Richards was killed on or around November 25.

Investigators later reconstructed the route of Richards’ vehicle, determining it traveled through Oklahoma on the way to South Dakota on November 27.

They identified a gap of one hour and nine minutes when the vehicle was near Sanders’ property in Marietta, Oklahoma. Investigators believe that window of time is when Sanders disposed of Richards’ body, likely on or near the property, before continuing north, according to the affidavit.

Sanders is currently in the Denton County Jail without bail.