U.S. Attorney General Eric Holder, shown speaking at the Congressional Black Caucus legislative conference on Friday, will be stepping down from his position as soon as a replacement is appointed. T.J. Kirkpatrick/Getty Images hide caption

itoggle caption T.J. Kirkpatrick/Getty Images

This undated file photo provided by the Arizona Department of Corrections shows inmate Joseph Rudolph Wood. No one on the Supreme Court objected publicly when the justices voted to let Arizona proceed with the execution of Wood, who unsuccessfully sought information about the drugs that would be used to kill him. AP hide caption

itoggle caption AP

Florida death row inmate Freddie Lee Hall challenged the state's use of an IQ cutoff to determine mental disability. The Supreme Court sided with him on Tuesday, saying Florida's law doesn't take standard errors of measurement into account. Florida Department of Corrections/AP hide caption

itoggle caption Florida Department of Corrections/AP

Death penalty opponents set up signs April 23 at the Florida State Prison near Starke, Fla., just hours before the execution of Robert Eugene Hendrix, 47, who killed his cousin and his cousin's wife to prevent him from testifying in a burglary case against him. Phil Sandlin/AP hide caption

itoggle caption Phil Sandlin/AP

Oklahoma Gov. Mary Fallin issues a statement to the media after the execution of Clayton Lockett. Oklahoma Secretary of Safety and Security Michael C. Thompson stands behind her at the Oklahoma State Capitol in Oklahoma City. Alonzo Adams/AP hide caption

itoggle caption Alonzo Adams/AP