The charges were dropped against a Chippewa County man originally arrested for being involved in a heroin ring.
A drug team arrested Kurtis Bruni for having heroin in October, but the Chippewa County prosecutor dismissed those charges last week.
Edward Willis Jr., Adam Glaser and Krysta Fike were also arrested for similar charges.
Willis is also facing charges for selling the drugs near a school.
A few weeks later, the Tri-DENT drug team arrested Ricky Munoz for delivery of heroin and Brandi Lee for delivery of morphine.
Tri-DENT is still investigating Armstrong and Bertram miller for similar crimes.