PLAISTOW — Two men and a woman were arrested in Plaistow Wednesday evening on drug charges after a two-month investigation. 

The members of the Rockingham County Sheriff Office Drug Task Force seized more than 750 grams of fentanyl and more than $60,000 from the trio. 

Margaret Herrmann, 33 of 24 Otterson Road, Londonderry, Joseph Grasso, 37 of 24 Otterson Road Londonderry, and Trevor Phillips, 27 of 179 Pine St. Manchester were each charged with three counts of distribution of fentanyl over 5 grams as well as possession of a narcotic drug with intent to distribute. 

All three pleaded not guilty in Rockingham County Superior Court Thursday, according to court records.

The deputies watched the trio over the course of two months in the Carriage Towne Plaza in Kingston.

In total, Phillips sold a confidential source more than 250 grams of heroin during the course of three sales, earning a revenue of $6,250. 

According to court documents, Deputy George P. Abele Jr. learned from a confidential source that Phillips was selling heroin fentanyl and cocaine. 

On May 9, the confidential source met Phillips, Grasso, and Herrmann at the Carriage Town Plaza. There, the source bought 50 grams of heroin for $1,250 from Phillips while Grasso and Herrmann acted as lookouts, according to court documents. 

On May 16, Phillips again sold the source 100 grams of heroin for $2,500, also in the Carriage Town Plaza in Kingston, according to court documents. 

Police attached a tracking device to the Nissan Sentra owned by Herrmann on June 5 while in the driveway of Grasso and Herrmann's Londonderry home, according to court documents.  

On June 6 a third transaction took place in the Carriage Town Plaza in Kingston where Grasso sold 100 grams of heroin to the source for $2,500, according to court documents. 

For the last sale, through a text message, Phillips agreed to sell 500 grams of fentanyl to the source, court documents say. 

Police then arrested Herrmann, Grasso, and Phillips Wednesday in the Walmart parking lot at 58 Plaistow Road.