Three times since 2010, Texas Attorney General Greg Abbott has determined that state officials must reveal the source of drugs used to execute criminals.Now he has changed his mind.Abbott told officials of the Texas Department of Criminal Justice on Thursday that they “must withhold the identifying information of the pharmacy and pharmacist” that are the state’s latest source of the drug used in death penalty cases.It’s understandable that the latest case might be different. The death penalty is fraught with controversy, and circumstances change rapidly where emotions run high.But what exactly has changed? Texans are left to guess. According to Abbott’s letter to TDCJ, a “threat assessment” from the Texas Department of Public Safety is what caused him to change his mind this time. But DPS won’t release that assessment or say whether any pharmacies are in danger or what the agency might be doing to investigate.A TDCJ spokesman told The Associated Press it’s all “law enforcement sensitive information.”Understandably, attorneys for Death Row inmates are sensitive about it, too. Their clients, even if they are the worst of the worst among criminals and have committed heinous acts, still deserve a transparent execution process so courts can decide whether it’s all being carried out properly.Texas and other death penalty states have struggled to find new sources of drugs after previous sources declined to continue. TDCJ wants to protect its current source.Previously, Abbott said no specific threat had been proven. Now he accepts what the DPS says.Inmate attorneys say they will appeal. Courts have a difficult issue to address. If attorneys can’t learn all the facts, they can’t fully defend their clients. That makes executions even more questionable than they are already.