Authorities in St. Louis County have confirmed the body found Friday afternoon at an abandoned glass factory in Valley Park is that of 6-year-old Cassandra “Casey” Williamson, who disappeared from a nearby home around 7:20 Friday morning. 24-year-old Johnny Johnson, described as a transient, was arrested and faces murder charges. Police say Johnson, who had spent the previous night in the same home in which the missing girl slept, has a criminal record. They say he has served prison time and is on probation for stealing firearms, felony theft, misdemeanor stealing and burglary. The offenses were committed in St. Louis County in 1997.