There have been more than 400 drug overdoses and at least five drug-related deaths in Missouri state prisons since May 2017, according to internal data from the Department of Corrections. In many cases, inmates have overdosed on controlled substances, including heroin and fentanyl. There are a number of ways drugs can be smuggled into prisons, but institutional corruption appears to play a role. Current and past DOC employees say staff members are bringing contraband into the prisons and selling it to inmates -- often without consequences.