Hysen Sherifi lectured federal Judge Earl Britt about Islamic teachings and warned the judge he faced damnation at his sentencing hearing.
Prosecutors say Sherifi conspired with his brother and a female friend to kill witnesses who testified against him about a plot with five other men in the Raleigh - Johnston County area to attack the U.S. Marine base at Quantico and targets overseas. In 2012, he was sentenced to 45 years in prison in the original case.
After Sherifi was convicted, prosecutors say he convinced his brother Shkumbin and former special education teacher Nevine Aly Elshiekh to help behead three confidential informants from his trial. He also wanted a fourth man killed who he said had defrauded his family out of more than $30,000.
The FBI learned of the plot through a jail informant and staged a fake hit on one of the witnesses. They even created bogus photos of the beheaded man to show to Hysen in his jail cell.
At sentencing Friday, Judge Britt said Hysen destroyed the lives of his brother and Elshiekh.
They were also sentenced Friday after pleading guilty last year to conspiracy to commit murder for hire at Hysen's urging. Shkumbin Sherifi was given 36 months in prison and 36 months probation. Nevine Aly Elshiekh was sentenced to 42 months in prison and 36 months probation.
Elshiek's lawyers asked Judge Britt for leniency in her sentencing Friday because they claimed she was under the influence of prescription drugs and was blinded by the romantic advances of Hysen. They said she was being treated for depression and was under "a wide variety" of prescription psychiatric drugs at the time of the conspiracy.
Elshiekh was friends of the family of one of Hysen's co-defendants in the original terror case, and she frequently made the two-hour trip to New Bern to attend the month-long trial, which began shortly after the 10th anniversary of the Sept. 11 attacks. She and Hysen began exchanging letters.
Elshiekh's lawyers said the medication she was taking and her history of childhood abuse made her vulnerable to the romantic advances of Hysen - who they say wooed her from his jail cell - sending her letters, convincing her to visit him in prison, and even proposing marriage.
Elshiekh had no criminal record, not even a speeding ticket, before she was arrested. Elshiek's lawyers said she did not understand the true nature of the plot and had limited involvement.
Prosecutors offered Elshiekh and Shkumbin plea deals, agreeing to drop eight other counts in exchange for testimony against Hysen.
"This case serves as an unfortunate reminder that we must remain ever vigilant in our efforts to detect violent extremists who seek to harm our people and property," said United States Attorney Thomas G. Walker in a statement after the sentencing.
ABC News and the Associated Press contributed to this report