St. Louis (KSDK) - Police say preliminary autopsy results show the 12-year-old Affton boy found in the Meramec River drowned.
Christopher Marks' body was recovered Tuesday afternoon from the Meramec River in Eureka.
Marks was with his family and friends at Pacific Palisades Conservation area when he took off to go swimming. His 15-year-old sister said they had all been drinking.
Toxicology tests will also be performed on Marks, but the results could take weeks to get back.
Investigators are working to see if alcohol may have played a role in Marks' death.