Three suspected marijuana growers face felony drug charges in separate cases that date back to 2015 and early 2016.

A fourth suspect also is charged with helping his father traffic in heroin two years ago.

The state police vice unit on Monday filed the cases at the office of District Judge Lewis Stoughton in Chicora after wrapping up a series of investigations, authorities said.

Charged with manufacturing a controlled substance, a felony, are Mark L. Boosel, 58, of Clay Township; Daniel Lee Digiacomo, 50, of Concord Township; and Lee Allen McCandless, 32, of Center Township.

The three men, who also face misdemeanor charges, are accused of growing marijuana at their homes.

Joshua Lee Pisor, 29, of Venango Township, a felon, is charged with conspiracy to deliver a controlled substance and illegally possessing a firearm, both felonies.

Pisor is already in the Butler County Prison, where he was booked Nov. 7 for failing to pay child support.

This week’s charges against Pisor stem from a 2015 investigation into suspected narcotics dealing out of his Stalker Road home, where he was living with his father, 47-year-old Richard H. Pisor Jr., according to court documents.

A search of the home turned up 179 stamp bags of heroin and 578 prescription pills that were stashed in a vinyl cooler.

A rifle also was found under a bed in the home’s basement where Joshua Pisor was living. Because of a 2007 conviction for burglary, he is barred by state law from possessing any firearms.

Richard Pisor admitted the heroin and pills “were his and that he sold it,” according to a police affidavit. He also implicated his son.

The elder Pisor told investigators that he provided Joshua Pisor with money to “pick up heroin” that he would in turn sell.

Police believe that the younger Pisor would travel to Cranberry Township to obtain the heroin for his father.

Richard Pisor was arrested immediately after the search of his home in June 2015. He subsequently pleaded guilty to heroin trafficking and in 2016 was sentenced to 3½ to 10 years in state prison.

He is currently serving his term at the State Correctional Institution-Laurel Highlands.

The charges against Boosel stem from a “knock and talk” visit at his home in the 1200 block of West Sunbury Road on Jan. 7, 2016.

Police eventually searched the house and seized four marijuana plants and grow materials, documents said. Officers also found a bag of processed marijuana and packaging items.

Suspicions of a marijuana-grow operation led police to Digiacomo’s home in the 1800 block of Oneida Valley Road on May 26, 2015, according to documents.

Police said they found three marijuana plants and other contraband.

A search of McCandless’ Swamp Run Road home on April 21, 2015, police said, yielded two grow rooms in the garage. Officers seized 60 marijuana plants, most of which were the “starter” variety, documents said.

Additional growing items, including lights, lamps, electric ballasts, thermometer, exhaust system and fertilizer, were confiscated.

Authorities on Wednesday said Boosel, Digiacomo and McCandless were to turn themselves in for arraignment at a still-to-be-determined date. It was not known when Pisor would be arraigned.