KANSAS CITY, Kan. -- A couple already accused of the videotaped sex killing of a suburban Kansas City woman were charged Friday with kidnapping and sexually assaulting a 5-year-old southeast Kansas girl.

Richard D. Davis, 41, and Dena D. Riley, 39, were charged with one count each of kidnapping. Federal prosecutor Eric Melgren said the girl was "seriously injured during a sexual assault" after Riley and Davis took her from her home in Arcadia. If convicted, they could face from 20 years to life in prison.

The pair already face charges in Jackson County, Mo., of first-degree murder, first-degree assault, kidnapping, forcible rape and forcible sodomy in the death of Marsha Spicer, whose sexual abuse and torture police say the couple videotaped. Her body was found May 15 in a shallow grave in Bates City, Mo., east of Kansas City.

The couple fled after Spicer's death and were captured May 25 in southwest Missouri with the 5-year-old girl, identified as Davis' niece.

Davis and Riley were being held without bond on the Missouri charges and did not yet have an attorney of record.

According to the complaint, Davis showed up at his half-sister's home on May 24 and convinced her that after spending 18 years in prison for rape and sodomy he had "turned his life around" and was planning to marry Riley.

Riley and Davis spent the night, and the next day they, the 5-year-old child, her father and another child went to visit another relative in Pittsburg. While in Pittsburg, the family went to lunch at a pizza parlor, but Davis and Riley said they instead wanted to take the girl to McDonald's, according to the complaint. When the pair did not return with the girl, the family notified police.

Later in the day, the Barton County, Mo., sheriff's office received a call from Riley, who told dispatchers she and Davis planned to kill themselves and were consuming both drugs and alcohol, according to court documents.

During that phone call, court documents say, Davis drove the pickup into a ditch and could not get the truck out.

After police arrived on the scene, they arrested Davis and Riley, and the girl was taken to a hospital. There, court documents say, a doctor determined the child had been sexually assaulted.

According to court documents, Riley and Davis both had to be treated for overdoses of drugs and alcohol.

Jackson County prosecutor Mike Sanders said Thursday that Davis and Riley also have admitted killing Michelle Ricci, although they have not been charged with her death.

Sanders said the couple told investigators that Ricci, 36, was sexually abused at their apartment in Independence, Mo., then tied up and driven to another Kansas City suburb, where she was strangled and her body set on fire.

Sanders said Davis had taken investigators to Ricci's body, which has not been positively identified.