Carlton, MN (Minnesota News Network)    A Minnesota man who sold a prescription pain-killing patch has been convicted of murder, after a buyer ate part of the patch and died from an overdose.

A Carlton County jury heard more than a week of testimony before convicting 52-year-old Robert Ferguson of Cloquet on third-degree murder.

Observers say it was a seldom-used charge until prosecutors began relying on it to convict drug suppliers in overdose deaths. Twenty-five year old Paul Mrosla of Carlton died in the driveway of his parents' house in January last year, soon after Mrosla bought Fentanyl  from Ferguson.

The defendant's daughter testified that she brought the victim and a friend to his father's house with the intent to buy the patch, and the two each took part of it. Ferguson testified he didn't know the men, and did not sell or give the drug to them.

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