Often depicted as the perfect poison in antiquated crime novels, cyanide – the drug police believe to be the cause of death of a lottery winner in Chicago shortly before he was to collect his winnings – is a potent, painful killer that essentially suffocates its victims. 

David Benjamin, a professor of biomedical forensic sciences at Boston University, said cyanide is the murder weapon of choice for some because it "can be used surreptitiously, it’s very potent and few drugs act as rapidly.”

Indeed, the Cook County medical examiner initially ruled the death 46-year-old Urooj Khan, a $1 million lottery winner, to be arteriosclerotic cardiovascular disease, a condition involving the hardening of arteries, after an external examination. No autopsy was performed, because there were not obvious injuries and no reason to suspect foul play. 

“Unless there’s significant trauma to the body, and without having a knife sticking out of the guy’s chest, the medical examiner will probably say, 'Oh, it was a cardiac event,'" Benjamin said.

But several days after Khan's body was released for burial, a family member approached the doctor who examined the body and suggested officials look into the matter further.

More in-depth toxicology tests, blood analysis and new screening results revealed a lethal level of cyanide in Khan's blood, according to the medical examiner's report. And with that, like something out of a Sherlock Holmes or Agatha Christie murder mystery, Khan’s official manner of death was ruled a homicide.

Poisoned lottery winner had no enemies, wife says

Usually found only in scientific labs, cyanide is a potent poison that can be ingested or inhaled. It cannot be legally purchased.

“It’s basically a poison that impedes your body’s ability to use oxygen,” Benjamin said. “It blocks the ability of your blood to circulate oxygen throughout your body, and you basically die from suffocation.”

Cyanide poisoning would probably feel “like someone had wrapped your face with Saran wrap,” he added.

Deborah Blum, an expert on poisons who wrote about the detectives who pioneered forensic toxicology in "The Poisoner’s Handbook: Murder and the Birth of Forensic Medicine in Jazz Age New York," said the once-popular homicidal poison essentially results in "this explosion of cell death." 

AP file

This undated photo provided by the Illinois Lottery shows Urooj Khan, 46, of Chicago's West Rogers Park neighborhood, posing with a winning lottery ticket.

But Blum said the use of cyanide in killings has become rare because it is difficult to obtain. It can also be easy to detect in some cases, leaving blue splotches on a victim's skin, making it less stealthy than killers would like.

"The thing about it is that it's not one of those poisons that's tasteless," Blum told The Associated Press. "It has a really strong, bitter taste, so you would know you had swallowed something bad if you had swallowed cyanide. But if you had a high enough dose it wouldn't matter, because ... a good lethal dose will take you out in less than five minutes."

Other cyanide poisonings have made headlines in recent years.

• A 42-year-old man in North Carolina poisoned himself in November of last year by ingesting or inhaling potassium cyanide. The incident prompted a hazardous material cleanup.
• The wife of a once-powerful Chinese politician admitted responsibility for poisoning British businessman Neil Heywood in November 2011 with cyanide over dinner. Heywood was found dead hours later in his hotel room. An internal Chinese report confirmed that he died from potassium cyanide added to his drink.
• An Ohio emergency room doctor was convicted of aggravated murder in March 2010 for lacing his wife's calcium supplement five years earlier with cyanide so he could be with his mistress. On that day, his wife, Rosemarie, collapsed while driving and crashed her SUV into another vehicle.  

Chicago Medical Examiner Stephen Cina, who is overseeing Khan's case, told the AP that out of 4,500 autopsies he has performed, he has only seen two incidences of cyanide poisoning.

Khan's body will be exhumed within the next two weeks, Cina said, in order to complete an investigation into his death.

A lottery winner was fatally poisoned with cyanide just as he was about to collect his payout on a $1 million instant lottery ticket, a Chicago medical examiner said Monday.

Urooj Khan died July 20, one day after the state issued a check to him for $425,000, which represented the after tax amount on the lump sum payout on his winning ticket. The check wasn’t cashed until Aug. 15, likely by a member of his estate.

After a limited exam, Cook County Medical Examiner Stephen Cina found no trauma or unusual substances in the 46-year-old's body, and the medical examiner's office declared that he died of natural causes.

Khan was buried at Rosehill Cemetery in Chicago, but within a week a concerned relative asked the medical examiner's office to take a closer look. 

“They had concerns that it was deemed a natural cause of death and wanted us to look harder,” Cina told NBCChicago.com. “And we did.”

The medical examiner’s office determined from comprehensive toxicology reports that Khan had ingested a deadly amount of cyanide and his death has been reclassified as a homicide.

Police are considering exhuming his body as part of the investigation.

Lottery winner killed by cyanide was immigrant, family man

“It’s a very lethal drug,” Cina said of the lethal dosage of cyanide investigators found in Khan’s toxicology samples. “It’s a chemical poison. It basically asphyxiates you at the biochemical level, so a little goes a long way.”

Khan bought his winning ticket at a 7-Eleven near his home in West Rogers Park, a neighborhood on Chicago's North Side. A native of India, he came to Chicago in the late 1980s and began working at a dry cleaners. He grew his business to include three Chicago-area dry cleaners, and reportedly planned to invest his lottery winnings in his stores.

He also planned to give some of his winnings to St. Jude Children’s Research Hospital.

Khan described his gleeful reaction to winning in a June press release from the Illinois Lottery. “I scratched the ticket, then I kept on saying, ‘I hit a million!’ over and over again,” Khan said. “I jumped two feet in the air, then ran back into the store and tipped the clerk $100.”

Khan’s wife declined an interview with NBCChicago.com outside one of her deceased husband’s dry cleaners. Her husband was a “kind and good-hearted person,” she said.

“He was a family man who worked hard for his family,” friend Jimmy Goreel told NBCChicago.com. “I just can’t see it happening. If that’s true, it’s sad."

The Associated Press contributed to this report. 

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