SOLANO COUNTY (CBS13) — It is a terrifying alleged “murder for hire” plot.

The Solano County District Attorney says a suspect in jail for sexually assaulting children, is now facing new charges for soliciting inmates to murder those child victims.

Rodney Scott Thomas is already locked up, but an undercover investigation by the DA, Solano County Sheriff’s Office, and Fairfield Police Department found Thomas trying to hire fellow inmates to kill two children he allegedly sexually assaulted.

Thomas, a big rig truck driver by trade, lived in a Vacaville apartment before his arrest.

Aaron Whiteside lived in the apartment directly across from Thomas for several years.

“He was basically trying to kill the witnesses,” Whiteside said. “That’s borderline psychopath.”

Whiteside said he never suspected his neighbor was capable of any of the crimes for which he’s accused.

“It’s scary the fact that the people that live right next to you, can be the polar opposite to what you would expect,” Whiteside said.

Court documents obtained by the Fairfield Daily Republic detail Thomas’ alleged plot.

According to the Daily Republic,  documents show “Thomas wanted to hire someone to commit a mass shooting at a local church or school the victims attended ‘so that it would not look like (the girls) were targeted.’”

The documents obtained by the Daily Republic also show an inmate helping with the investigation wore a wire during one meeting with Thomas on his plan.

“More terrifying than I really want to have my neighborhood be,” Whiteside said.

Arrested on charges he preyed on children. Now startling new allegations of a “murder for hire” plot, conceived by an inmate already in custody.

Thomas is due back in court Sept. 5, to face the new charges.