51-year-old Priscilla Ellis was charged with murder-for-hire, witness retaliation and securities counterfeiting.
The 65-year-sentence will run consecutive to a 40-year sentence she was already serving.
According to court documents, Ellis and her two co-defendants were convicted of conspiracies to commit international money laundering and mail and wire fraud.
Ellis then began soliciting other inmates to help her find a hitman to murder one of the witnesses who testified during her trial, as well as the mother of a second trial witness.
Meanwhile, she directed coconspirators in Nigeria and Texas to create electronic images of counterfeit cashier’s checks with face values totaling hundreds of thousands of dollars that were to be cashed and used to pay for the murders.
She then "hired" an undercover FBI agent posing as a hitman and provided instructions on how she wanted her targets killed.
On Oct. 28, 2016, a family member acting at Ellis' direction provided a down payment on the murder contracts to the undercover agent.
Ultimately Ellis was convicted, resulting in the 65-year-sentence.