Use of heroin in Pennsylvania has increased drastically in recent years, and authorities are fighting back.

"We're really in the midst of a crisis with regards to heroin overdoses and deaths," said Lebanon County District Attorney Dave Arnold.

Arnold and Pennsylvania State Police with Reading-based Troop L announced criminal charges Tuesday in connection with two deadly drug overdoses in Lebanon County.

"We're going to continue to prosecute dealers. We're going to continue to prosecute specifically those who are selling heroin and killing our citizens," said Arnold.

Edwin Mowrer, Jose Gonzalez, Mollie Mavretic and Junior Estevez have all been charged with "drug delivery resulting in death," a felony of the first-degree.

"It's important to get anyone off the streets that's dealing drugs," said Trooper Norbert Brennan, who worked on the investigation.

"One of the individuals was considered a pretty big player," Brennen said.

State police said Mowrer and Gonzalez supplied heroin to Robert Marshall of Jackson Township, Lebanon County. Marshall fatally overdosed on August 15, 2015.

State police said Mavretic and Estevez supplied heroin laced with fentanyl to Dylan Yiengst. Yiengst, of Union Township, Lebanon County, fatally overdosed on January 1, 2016.

Both victims died at the age of 24.

"Ultimately, it's a supply and demand issue, and we certainly try to cut into the supply that's available. I think our society has an obligation to cut into the demand for it," said Arnold.

Officials said prosecuting dealers is not enough. They said Pennsylvania needs more education and treatment programs.

"People who continue to sell heroin, we're going to continue to investigate them and lock 'em up for as long as we can, and that's where they belong quite frankly," said Arnold.

According to the U.S. Centers for Disease Control and Prevention, more people died from drug overdoses in 2014 than any other year on record.

Officials said they'll continue to crack down on heroin suppliers just like they did in this case.