A source close to the investigation of the videotaped rape and murder of 41-year-old Marsha Spicer tells FOX News that police found additional evidence connected to the case.

The evidence was found in Monday in Lafayette County, Mo. — the same county where Spicer's body was found in a shallow grave on May 15.

On Saturday, police found a second body in Clay County, Mo., believed to be that of 36-year-old Michelle Ricci, the source says. Information on the whereabouts of the bodies was gleaned through jailhouse interviews with suspects Richard Davis and Dena Riley, who are already charged with first-degree murder, first-degree assault, kidnapping, forcible rape and two counts of forcible sodomy.

Arraignment for Davis and Riley is scheduled for 11 a.m. CDT Tuesday in Jackson County, Missouri Circuit Court. Additional charges are expected in the coming days for yet unspecified crimes.

Although a spokesman for Jackson County Missouri prosecutor refused comment, Ricci's mother, Sherry Ballew, said that Independence, Mo., police notified her Sunday that a body had been found and brought the family to the police department to submit DNA samples. The family was also asked specific questions about a back surgery Ricci had performed.

After the murder of Spicer, Ballew asked for the public's help with information about her daughter. She told the press that her daughter was acquainted with Davis and that she feared for her daughter's life. She also said her daughter was the woman whom Independence police were trying to locate through a picture released by the department. That picture was an image captured from a videotape seized at the home shared by Davis and Riley.

Ricci was reported missing May 3, after she failed to go to her mother's house. Ballew told police she had last seen Ricci on April 2 and that Ricci was with her boyfriend at the time. The house that Ricci shared with her boyfriend burned down on April 12.

FOX News' Jeff Goldblatt and the Associated Press contributed to this report.