Two people are set to die by lethal injection Tuesday night. Barring any last minute appeals, Charles Singleton and Karl Roberts will be put to death by lethal injection at Cummins Prison. Singleton has been on death row since 1980. He killed Mary Lou York in Hamburg. Roberts has been on death row since 2000. He killed his 12 year old niece, Andria Nicole Brewer in Polk County. The Singleton case has gathered global attention, because Singleton controls his sanity with medication. Although the constitution prohibits the execution of a mentally insane individual, the courts have not overturned Singleton`s sentence. Singleton is set for execution at 8 tomorrow night, Roberts execution will immediately follow.