Kansas City, Mo. ? Two suspects accused of videotaping the rape of a woman and killing her might have other victims in their past, authorities said Saturday.

Additional charges are likely, said Ken Evans, spokesman for Jackson County Prosecutor Mike Sanders.

“One of the items of the investigation is possible links to other missing persons,” Evans said.

Richard D. Davis, 41, and Dena D. Riley, 39, were arrested Thursday after crashing their truck, ending eight days on the run. Davis was treated for injuries and turned over to police in Independence. Riley remained in a hospital in Joplin, Mo.

With them when they were arrested was a 5-year-old girl who had been taken from a town near Pittsburg, Kan. Police said Saturday she was hospitalized in Kansas City with serious injuries, but a hospital spokesman would not say whether she was still there.

The FBI has initiated a kidnapping investigation. Davis and Riley could face a federal kidnapping charge because the girl was moved across a state line. Police have said the girl is Davis’ niece.

Davis and Riley are charged with killing Marsha Spicer, 41, who was seen being beaten, sexually assaulted and strangled on a videotape found at the Independence apartment of Davis and Riley.

Spicer’s body was found May 15 in a shallow grave near Bates City, Mo.

In the small town where the girl was taken, neighbor Heather McBride said she had met Davis on Wednesday. He was in her backyard, where McBride’s daughter and other children were playing, and told McBride he was looking for the girl, she said.

“I had no idea who he was,” McBride said. “When I found out, I almost kicked myself in the head. I could have prevented this.”

Pittsburg police said the girl’s parents told authorities that their daughter had gone to a restaurant with Davis and a female companion on Thursday.

After the girl’s parents reported her missing, the Barton County Sheriff’s Department got a 911 call from Riley. Authorities said she told a deputy that she and Davis were going to harm themselves. Deputies later found the wrecked truck as well as the couple and the girl.