Ashlee Simpson will play murderous Roxie Hart in the stage production of Chicago in October. The 21-year-old has been offered the role and will join the cast of the show in either London or on the Broadway stage in New York City. A source close to Simpson tells American publication Us Weekly, "She will probably choose London." Earlier this year, Rita Wilson stepped into the role in New York. Although Simpson has little experience in musical theatre, she has been a back-up dancer on her sister Jessica's tour and had a role on US family drama 7th Heaven. The singer has said she wants to focus on her acting career.