Police in Maryland say a person of interest has been identified in the 1975 disappearance of two sisters from a Montgomery County shopping mall.
County police said Monday the person they want to question is a convicted child sex offender who is currently incarcerated in another state. Police say the man had traveled extensively around the country.
Authorities expect to release more information at a news conference Tuesday, including about why the man is considered a person of interest.
The announcement could represent a significant break in the investigation into the disappearance of 12-year-old Sheila Lyon and her 10-year-old sister Katherine. The girls went missing after walking to a nearby shopping center, the Westfield Wheaton Mall.