The Parker County Sheriff’s Office revealed charges against five people who are accused of running a scam that bilked county residents out of $1.2 million.

Investigators started pursuing the case in April, the sheriff’s office said in a news release. Multiple victims had filed complaints reporting that scammers had posed as employees of the sheriff’s office and demanded payments to settle outstanding warrants or missed jury duty. The suspects instructed victims victims to purchase cryptocurrency through bitcoin ATMs, then transfer the funds to wallets owned by the scammers, authorities said.

Investigators were able to obtain search warrants for banking, phone and internet records and identified five suspects. Two of them are in Texas and three are in Georgia, the sheriff’s office said.

The alleged ringleader of the scam was identified as 25-year-old Jose Joaquin Gaona, who is currently serving a 71-year prison sentence in Georgia for multiple convictions of violent felonies. Gaona allegedly obtained a cellphone in prison, which he used to direct the scam. He even called victims from his prison cell, the sheriff’s office said. Some of the stolen money was allegedly deposited into a prison account.

Dallas County resident Romelia Barrientos Garcia, 46, and Bexar County resident Christian de la Pena, 24, and 38-year-old Samantha Ann Flores of Atlanta were all charged with engaging in organized criminal activity and arrested. 

A fifth suspect, identified as 25-year-old Towkir Islam, is at large and believed to be in Georgia. He is also charged with engaging in organized criminal activity.

“The amount of scam cases, stolen funds and future victims which have been prevented with these arrests will likely never be measured or determined,” Parker County Sheriff Russ Authier said in a statement. “I would like to thank my investigators and the cooperating agencies for their invaluable assistance in this investigation, and for taking part in this operation.”

Authier also said the sheriff’s department would never call people demanding money in to settle a warrant, and urged the public to verify the identity of anyone asking for money.