CEDAR PARK, Texas (KXAN) — The Cedar Park Police Department arrested nearly a dozen people suspected of selling drugs laced with fentanyl.

During a Tuesday morning drug bust, the Cedar Park Police Department said they issued 13 federal indictments and have arrested 10 so far.

“This is a regional investigation and we’ve been working a lot with our regional partners throughout Central Texas — from San Antonio to Cedar Park — and across four states, as well,” said Cedar Park Police Commander Darlene Lewis.

Lewis told KXAN on Tuesday that Cedar Park began investing resources in tracking down the accusers two years ago when Cedar Park began noticing a spike in overdoses due to counterfeit pills.

“We had 23 overdoses and nine of those results in fatalities in the last two years,” said Lewis.

The 10 arrested so far are charged with conspiracy to distribute and some are charged with possession with intent to distribute, Lewis said.

“For this investigation, we have seized over 100,000 counterfeit oxycodone pills that have been laced with fentanyl. The street value for these is over $1 million,” said Lewis.

The pills that have been confiscated by the CPPD will be sent to a DEA crime lab to be examined.

The Cedar Park Police Department says they used information gathered from the 13 overdoses and nine fatalities to find out where the pills were coming from, which led their investigation to Arizona, Oregon, California and Texas.

“The majority of the people are coming from the Austin area, but we do have a couple of people in other states that we have arrested,” said Tyson Hodges, Assistant Special Agent at Charge, Austin District DEA Office.

DEA agent Tyson Hodges spoke with KXAN and said the alarming part of all of this is that many of the victims thought they were getting a painkiller — and unknowingly took pills laced with a deadly drug.

“A lot of these are young adults that are obtaining these pills that’s resulting in these fatalities where they are thinking that it’s just one pill, or they’re obtaining it from a friend or someone they know,” said Lewis.

Other agencies such as the Department of Homeland Security, the United States Postal Service, the FBI and then DEA were also part of the investigation.

The DEA believes the drugs are coming through Mexico. From here, investigators plan to identify those supply routes and start addressing them.

“I don’t believe that this investigation is complete. It’s not liked its coming to the end of a two-year investigation, but it’s not over with,” said Lewis. “I know that we can’t bring anyone’s life back, but we do hope that this brings some closure knowing that we’ve worked hard in this investigation to hold those responsible for those deaths.”