Arkansas and at least a dozen other states with the death penalty have been keeping secret how and where they are getting the lethal drugs for their death chambers - information that had long been publicly available.
The secrecy has helped blunt legal challenges over the lethal injection drugs, which states have had trouble obtaining in recent years because manufacturers don't want their drugs used in executions.
In recent rulings, state and federal courts across the country have upheld the legality of the new secrecy laws, despite opponents' complaints.
"These secrecy statutes are extremely effective at preventing challenges to execution procedures," said Megan McCracken, an attorney at the University of California at Berkeley Law School's Death Penalty Clinic.
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