Saline County Prosecutor Robert Herzfeld has ended his investigation into Steven Gamblin`s death after an autopsy report shows he died of a drug overdose. The report, which took six months to complete, showed traces of marijuana in Gamblin`s system. Medical examiners listed a "probable drug intoxication as the cause of death." "He took a lot of drugs over a long period of time and it caught up with him," said Herzfeld. Shannon Hills Police initially believed Gamblin smoked a marijuana cigarette laced with snake venom. Medical examiners says that`s scientifically impossible because venom breaks down when it comes in contact with heat.