On September 28, 1981, James Foster (defendant) approached John Ragsdale to enlist his help in robbing an elderly man named A.O. Hedrick. Once Ragsdale ascertained that Foster was serious, he decided to find out more information from Foster in order to turn him over to the police. Ragsdale told police that the robbery would occur on October 3. On that day, Foster and Ragsdale met at Hedrick’s home, where they were met by police. Foster was arrested and charged with conspiracy. A jury convicted Foster of conspiracy to commit robbery. The appellate court reversed Foster's conviction, holding that the crime of conspiracy requires an actual agreement between at least two people (i.e., the bilateral theory of conspiracy), and Ragsdale had only pretended to agree to Foster's plan for the robbery. The people of the State of Illinois (plaintiff) appealed to the Illinois Supreme Court. On appeal, the state argued that the crime of conspiracy only requires one person's intent to agree to commit a crime (i.e., the unilateral theory of conspiracy), or, alternatively, that there was enough evidence to convict Foster under the bilateral theory.