The American Civil Liberties Union says Colorado's instructions for putting prisoners to death by lethal injection have been revised to include an alternate drug, underscoring problems in carrying out executions.
The ACLU on Friday released a copy of the instructions, which it obtained after filing suit against the Department of Corrections.
The instructions include a list of three drugs to use for executions, along with an alternate for one of the drugs, sodium pentothal.
The ACLU says that's a change from a 2011 version of the instructions and shows that sodium pentothal has become hard to get.
A Department of Corrections spokeswoman says she can't confirm whether the instructions have changed. But she acknowledges sodium pentothal has become scarce and notes state law allows the use of a substitute.