BLOOMINGTON, Ill. (AP) — A central Illinois woman and a man have pleaded not guilty to murder charges in the stabbing death of the woman's mother.

The (Bloomington) Pantagraph ( ) reports that in separate court hearings, 22-year-old Christine Roush of Washington and 20-year-old Matthew Isabell of Marquette Heights entered their pleas in McLean County Circuit Court.

Friday's hearings come weeks after the body East Peoria resident Teresa Ann Poehlman's was found July 2 by hikers on a trail in the Funks Grove Nature Preserve.

Prosecutors say Roush told Isabell that she planned to kill her mother and that he knew the reason they were going to the nature preserve.

Authorities say continue to search for a third suspect in Poehlman's death.

Roush and Isabell are scheduled to return to court on Sept. 5.