An attorney for a man scheduled to be put to death in Missouri next month said Wednesday that she has "very serious concerns" about the state's lethal injection method after an online news outlet reported that Missouri bought execution drugs from a compounding pharmacy with a troubling record.

The comments from attorney Cheryl Pilate came after Buzzfeed News reported a day earlier that Foundation Care pharmacy of suburban St. Louis was the supplier of pentobarbital used in the 17 Missouri executions since 2014, even though the Food and Drug Administration deemed Foundation Care a "high-risk" pharmacy. Buzzfeed cited two people with knowledge of the matter who spoke on the condition of anonymity because of strict state laws prohibiting disclosure or publishing of the identity of the supplier.

Pilate's client, Russell Bucklew, 49, is scheduled to die March 20 for killing his ex-girlfriend's new boyfriend in 1996. It would be the state's first execution since January 2017.

"The Buzzfeed article raised a lot of questions and has prompted some very serious concerns," Pilate said in a phone interview. "We did not know these things."

The quality of the execution drug is of particular concern in Bucklew's case because he suffers from a rare medical condition known as cavernous hemangioma, which causes weakened and malformed blood vessels. Pilate said Bucklew also has a "collection of blood-filled, unstable tumors" in his nose and throat.

An appeal already pending before the 8th U.S. Circuit Court of Appeals claims that because of his condition, the execution runs the risk of constitutionally-prohibited cruel and unusual punishment. Pilate said she wants more information before deciding whether to file a new appeal.

The Missouri Department of Corrections declined comment and has declined to say whether Foundation Care was its provider of pentobarbital.

Centene Corp. of suburban St. Louis purchased Foundation Care in October. Centene spokeswoman Marcela Manjarrez Hawn said that under Centene's ownership, Foundation Care "has never supplied, and will never supply" drugs for executions. But she did not say whether Foundation Care provided execution drugs before it was purchased by Centene.

Foundation Care was flagged as a "high-risk" pharmacy by the FDA in 2013, Buzzfeed reported. In 2014, the FDA sent a letter to the Missouri Board of Pharmacy warning that the pharmacy's practices "could lead to contamination of drugs, potentially putting patients at risk."

None of the 20 inmates executed since Missouri began using pentobarbital in 2013 have shown obvious signs of pain or suffering.

One Missouri lawmaker said the state should consider using fentanyl, a synthetic opiate responsible for thousands of overdose deaths. Republican Rep. Shane Roden said fentanyl would be easier to get and would put the inmate in a "very subtle, peaceful sleep" before stopping his heart.

According to court documents, Bucklew was angry at his girlfriend for leaving him and moving in with Michael Sanders of Cape Girardeau when he tracked her down at Sanders' home in March 2016. He killed Sanders in front of the woman, her two daughters and Sanders' two sons, the documents say. He then attacked the woman and drove her to a secluded area and raped her, the court record says.

After a state trooper spotted Bucklew's car, Bucklew shot at the trooper but missed, court records say. Bucklew later escaped from jail, hid in the home of the ex-girlfriend's mother and beat her with a hammer, according to court documents.

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