Jackson's 3-month-old son was found in an inside hallway of an apartment complex in Breckenridge Hills at 5 a.m. Friday. The child was in a car seat and was in good health.
Jackson is originally from East St. Louis, Ill., but now lives in Oklahoma City. She was reportedly coming to the St. Louis area for a visit last week but relatives have not heard from her since Thursday.
The newspaper reported that the cause of death had not been determined.