INDEPENDENCE, MO. ? A couple accused of videotaping the rape of an Independence woman and killing her had a 5-year-old girl with them when they turned themselves in Thursday evening, the FBI said.

Richard Davis and Dena Riley were taken into custody about 6 p.m. in the southwest Missouri town of Lamar, Jackson County prosecutors said.

Jeff Lanza, an FBI spokesman in Kansas City, said federal investigators believe the girl was taken across state lines.

“We believe this girl was taken from her home in Pittsburg, Kansas, and the FBI is investigating this as a kidnapping case,” he told The Associated Press in a telephone interview.

Pittsburg is in southeast Kansas, about 17 miles from Lamar.

Lanza said authorities were trying to determine any possible relationship between the girl and the couple. He also said authorities would try to determine whether she was a victim of a sex crime.

Prosecutor Mike Sanders declined to discuss the circumstances surrounding the surrender of Davis and Riley. He said he expected them to be returned to Independence within the next 24 hours.

“It’s fair to say these were two of the most wanted people in America, and tonight they are in custody,” he said. “So I think we can all breathe a sigh of relief.”

Davis, 41, and Riley, 39, were charged Monday.

Each is charged with first-degree murder, first-degree assault, kidnapping, forcible rape and two counts of forcible sodomy in the strangulation death of Marsha Spicer. Her naked body was found May 15 in a shallow grave near Bates City, east of Kansas City.

Sanders said his office would review the case to determine whether to pursue the death penalty.

Spicer’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,” said Schumacher, of Blue Springs. “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.”

Police say the video found on a TV stand in the couple’s Independence apartment shows the 41-year-old Spicer with duct tape over her eyes and her hands secured behind her back. She is beaten, raped and sodomized as she pleads for the attack to stop.

The room portrayed on tape matches the bedroom at the home of Davis and Riley, police said, and detectives noted that 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.”

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

The Missouri State Highway Patrol followed them to Perryville, south of St. Louis, and on Sunday interviewed a woman about the couple’s disappearance. Police later learned the couple had been hiding in the back room of the woman’s apartment and escaped after officers left. The woman, Susan Summers, has been charged with two counts of hindering prosecution.

Sanders said officers had worked shifts of more than 24 hours straight as the search continued. He said the publicity the case had generated made it difficult for the couple to stay on the run.

“They knew we were very close to catching them,” he said.

Several family members and friends of the suspects have told detectives the couple had hopes of carrying out similar acts on others, but police say they’re unsure how valid those claims are.

Sanders said Thursday that the investigation continues and that more charges are “very likely in the near future.”

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.

Earlier in the day, police searched fields, woods and the banks of a creek in the area north of Bates City where Spicer’s body was found. Police said only that they were looking for evidence.

Independence Police Chief Fred Mills declined to say whether authorities had thought that Davis and Riley might be in southwest Missouri or whether the two had ties to that area.

“It’s one of those things we really can’t discuss,” Mills said.