WASHINGTON -- A bipartisan panel of justice experts recommends states stop using a drug "cocktail" for death penalty lethal injections.

"States are urged to adopt a one-drug protocol that achieves death by an overdose of a single anesthetic or barbiturate, as opposed to the three-drug method," The Constitution Project's Death Penalty Committee recommended in a report Wednesday. "A one-drug method would decrease the problems associated with drug administration and eliminate the risks from using paralyzing or painful chemical agents."

The report notes that a one-drug method is preferred by veterinarians euthanizing animals because it is "more humane and less prone to error."

Oklahoma used a three drug cocktail from sources it won't disclose in the botched execution of murderer Clayton Lockett last week.

The Constitution Project’s Death Penalty Committee, a group that includes criminal justice experts and former elected officials, made 38 other recommendations in the report. The Constitution Project is a bipartisan think tank based in Washington.

“From the moment of arrest to the moment of death, the criminal justice system faces vexing challenges in carrying out the ultimate punishment,” former Texas Gov. Mark White (D), a co-chair of the committee who oversaw 19 executions, said in a statement.