On Sunday, after an investigation lasting over seven months, detectives from the Lincoln County Sheriff's Office served a search warrant on a Libby residence and made three arrests on drug charges. The search warrant was served on the residence of Margaret Doubek at 147 Voves Ave. in Libby, according to a press release issued by Lincoln County Sheriff Daryl Anderson. During the search, detectives seized several items of evidence related to dangerous drugs, including suspected methamphetamine, marijuana and prescription narcotics, according to the press release. Three adults were arrested on felony drug charges and are currently being held in the Lincoln County Detention Facility. Doubek, 51, was arrested on one count each of possession of dangerous drugs with intent to distribute, criminal endangerment, possession of drug paraphernalia and a misdemeanor possession of dangerous drugs. Doubek also has five counts of felony possession of dangerous drugs charged against her, the press release stated. Cassandra Doubek, 20, was arrested on two counts of felony possession of dangerous drugs and one count each of misdemeanor possession of dangerous drugs and possession of drug paraphernalia, according to the press release. Kara Beadreau, 36, was arrested on two counts of felony possession of dangerous drugs, said the press release. The investigation is ongoing and detectives expect to file additional charges.