DENVER (CBS4) – Three owners of the Sweet Leaf marijuana dispensaries will spend a year in prison and a year on parole. The sentence comes after they pleaded guilty Friday to violating Colorado’s organized crime acts and illegally selling marijuana.

(credit: CBS)

Investigators say those dispensaries were letting people make multiple purchases of pot on the same day at the dispensaries and thereby violating state law. “Looping” alleges that the same buyer returns multiple times in a row to buy more marijuana than permitted in Colorado statute.

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The prison sentences and the probation time for owners Matthew Aiken, 40, Christian Johnson, 50, and Anthony Sauro, 30, will run concurrently.

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The investigation was launched after a tip.

“This case began thanks to a watchful citizen who observed the same people making multiple purchases of marijuana from a single Sweet Leaf dispensary in one day and tipped off the Denver Police Department,” said Denver District Attorney Beth McCann in a prepared statement.

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A total of 18 budtenders initially faced charges. Those charges were later dropped.