Florida prepares to execute Duane Owen for 1984 murders and rapes.

Duane Owen, one of the longest-held inmates on Florida's death row, is set to be executed for two separate killings in 1984, the fatal stabbing of a 14-year-old babysitter as two children in her care were sleeping and the other a hammer attack on a mother of two. Owen is one of 293 people on Florida’s death row and one of the longest residing there. His lawyers argued that he shouldn't be executed on grounds of insanity, but the state Supreme Court rejected his latest appeal last week and the U.S. Supreme Court rejected it Wednesday.