A Kansas City man was sentenced Friday in federal court for possessing the synthetic opioid carfentanil to distribute after a Grain Valley teenager nearly died from an overdose after ingesting one of the carfentanil pills.

Greg Lankas, 21, was sentenced to 15 years to federal prison without parole. He had pleaded guilty last October to possessing carfentanil with the intent to distribute.

According to court documents, the investigation leading to Lankas began Aug. 2, 2017, when Grain Valley police officers responded to a drug overdose. A 17-year-old said he thought he'd snorted a half-pill of oxycodone, but it was actually carfentanil, which is estimated to be 10,000 times more potent than morphine and 100 times more potent than fentanyl, which itself is 50 times more potent than heroin.

At the teen's home, officers located 375 pills stamped “XANAX” on one side and a sideways “2” on the other. They also found some other pills stamped “A215.” The teen told police he got the pills from Lankas in the Westport neighborhood of Kansas City, then took a few Xanax pills and snorted the half-pill. He immediately blacked out and does not remember anything except waking up and passing out again in the ambulance. He told officers he had snorted oxycodone before and could not understand his reaction.

Three days later, Kansas City police officers responded to a suicidal person report. A woman said she and Lankas, her boyfriend, had been arguing and he threatened to jump out of the apartment window and take a handful of pills. Police arrested Lankas and found a large stack of white pills sitting on the kitchen table – more than 1,300 – as well as 67 partial pills stamped “XANAX” and 3.25 blue pills stamped “A215” (later determined to contain carfentanil), $6,583 inside a safe in the bedroom and drug paraphernalia.

According the court documents, Lankas told officers that he purchased the pills on the dark web and admitted that he intended to distribute them.