A couple accused of videotaping the rape of a woman and killing her were arrested when they called 911 after a car accident and told a deputy they planned to hurt themselves, authorities said Friday.

Richard Davis and Dena Riley, who lived together in Independence, Mo., were arrested Thursday evening after having dinner with a 5-year-old niece of Davis' in Pittsburg, Kan. The girl's parents reported her missing when she was not returned home after several hours, police said.

The couple was being sought after on charges that they sexually assaulted, beat and strangled 41-year-old Marsha Spicer and buried her in a shallow grave in a rural area in Bates City, Mo.

Riley placed a 911 call when the truck they were driving was involved in a crash, and told a deputy she and Davis planned to hurt themselves, Barton County Sheriff Shannon Higgins said. Authorities offered no further details and would not immediately release a transcript of the call.

Both suspects were transported to hospitals. Riley remained hospitalized Friday, authorities said, but information on the extent of her injuries and whether they were sustained in the crash was not released. Davis was released from the hospital and was being held in Independence awaiting arraignment.

Police have not said whether the girl was sexually abused. FBI spokesman Michael Pettry said Friday that authorities were continuing their investigation and looking into possible federal kidnapping charges.

Davis, 41, and Riley, 39, are already charged with first-degree murder, first-degree assault, kidnapping, forcible rape and two counts of forcible sodomy in the death of Marsha Spicer. Her naked body was found May 15 in a shallow grave, a day after she was believed to have been strangled.

Police found a videotape of the activities leading up to Spicer's death and her murder in the couple's apartment. The couple had been on the run since May 19, when police discovered the tape.

"We’ve had some pretty heinous crimes around here, but nothing of this particular nature," FBI Special Agent Jeff Lanza told FOX News.

Police had interviewed the couple last week, but they fled soon after, before authorities obtained a search warrant and found the videotape.

Officials said the video found on a TV stand in the couple's apartment shows Spicer, 41, with duct tape over her eyes and her hands behind her back. She is beaten, raped and sodomized as she pleads for the attack to stop, police said.

Sanders said the tape was so disturbing that there was talk of offering counseling to those involved in investigating the case.

The victim's sister, Jackie Schumacher, called Davis and Riley "demented perverts that shouldn't live."

"Nobody should do what they did to Marsha or anybody else," the Blue Springs woman said. "People don't deserve to be treated the way that she was treated. I haven't seen the tape. I don't want to see the tape, but I've heard — and nobody, nobody should be treated the way she was treated."

The room portrayed on the tape matches their bedroom, police said, and detectives noted the couple had a camcorder aimed at their bed when officers interviewed them. Officers also say a notebook at the home made references to "sexual desires," "choking," "chasing" and "victims."

Davis is on parole after spending nearly 18 years in prison for a 1987 rape and sodomy conviction. Riley has previously been charged with misdemeanors, but no felonies.

Sources told FOX News that additional victims of the hunted couple are likely but that no bodies have been found. Some of the female victims also are believed to have been videotaped.

"America's Most Wanted" reported that it was known that the two were preparing to commit suicide and they took "a lot" of pills before contacting police to tell them they had the young girl and wanted to make sure she was returned to her parents.

Spicer is survived by two children and two grandchildren.

FOXNews' Jeff Goldblatt and The Associated Press contributed to this report.