MEMPHIS, Tenn. — Four people in West Memphis, Arkansas were indicted by a federal grand jury on charges in a human trafficking case.

State Prosecuting Attorney Keith L. Chrestman did not release the names of the four people indicted when he made the announcement Monday, but his office confirmed that the defendants are the same people identified by West Memphis Police in a rape and sex assault case earlier this year: Ricky Gaines, Victoria McClure, Bryan Donaldson and Randle Blair.

The Crittenden County Public Defender’s Office confirmed Donaldson is a former public defender who is no longer with the office. They had no comment.

The investigation began Jan. 9 of this year after a 17-year-old girl with no identification was found walking around the parking lot of the Walmart Supercenter in West Memphis, asking for help, Chrestman’s office said in a news release.

The girl told authorities she was from Phoenix and had been taken to West Memphis to work as a prostitute. She said she’d been sexually assaulted.

Chrestman said subpoenaed text messages from the accused traffickers revealed they were planning to send another woman to West Memphis, saying “We have another girl … .”

“We may have saved someone’s life,” Crittenden County Prosecuting Attorney Michael Snell said in the release.

State prosecutors had already charged four people in the case, Chrestman’s office said — two men were charged with multiple rape counts; a third man with multiple rape counts, kidnapping, and trafficking; and a woman with kidnapping and trafficking.

Snell said those state charges would be dismissed once the federal charges were imposed.

In a separate news release Monday, West Memphis Police said a saturation effort had resulted in the arrests of eight people — including Donaldson, Gaines, McClure and Blair.

It was unclear whether the four faced new charges or were being arrested in connection to the federal indictment.

Police said the Crittenden County Sheriff’s Office, State Police, ATF, and the US Marshals were “targeting violent fugitives and criminal offenders who committed high-profile crimes such as homicide, felony assault, and sexual assault, illegal possession of firearms, illegal drug distribution, robbery, and arson.”