A death row prisoner in Texas is seeking to delay his execution following last week’s botched killing in Oklahoma. The attorney for Robert Campbell says his client could face the same fate as Clayton Lockett, who died of a heart attack more than 40 minutes after being injected with untested drugs. A second autopsy is now being carried out on Lockett one week after his death. Meanwhile, lawyers for the prisoner who was set for execution right after Lockett, Charles Warner, have asked a court to stay his killing for six months. He is due to be executed in six days.