DEVELOPING: The FBI has captured one of two additional suspects in the abduction of a North Carolina assistant prosecutor's father nearly two weeks ago.
Quantavious Thompson was apprehended by federal authorities for his alleged role in the April 5 abduction of Frank Aurthur Janssen. Thompson is the seventh person to be arrested in what the FBI has called an "elaborate plot" to kill Janssen because his prosecutor daughter, Assistant District Attorney Colleen Janssen, sent a gang member to jail for life.
An eighth suspect, 20-year-old Jakym "Jak" Camel Tibbs, remains at large. Tibbs, who is from New York, is considered armed and dangerous. A $25,000 reward is being offered for information leading to his arrest.
Janssen, a military contractor, was taken from his Wake Forest, N.C., home and rescued last Wednesday during a late-night raid by the FBI at an Atlanta apartment complex.
The FBI claims the scheme was masterminded by Kelvin Melton, via text message from his prison cell. Melton, 49, a high-ranking member of the Bloods street gang from New York City, was convicted in October 2012 of assault with a deadly weapon with intent to kill inflicting serious injury and of being a habitual felon. He also now faces a charge of conspiracy to kidnap.
Authorities allege Melton sent more than 120 texts that included threats of torture to Janssen's wife and instructions to the alleged kidnappers on how to kill Janssen and dispose of his body, according to Fox afilliate WRAL-TV.
Criminal complaints against Tibbs and Thompson allege that the pair used a stun gun on the 63-year-old Janssen when he answered the door of his home and then took him to Atlanta, where the FBI's Hostage Rescue Team freed him just before midnight on April 9, according to court documents.
The complaints also allege the kidnappers stopped at a McDonald's in Lexington, S.C., on their way to Wake Forest and that a receipt from that McDonald's was later found on the floor at Janssen's home, where it was apparently dropped during the assault, the station reported.
Authorities later recovered security camera footage from the fast-food restaurant showing Tibbs and Thompson.
Once in Atlanta, the alleged kidnappers sent Janssen's wife photos of him tied to a chair along with text messages threatening to cut him into pieces if their demands were not met. Authorities have not said specifically what the demands were -- only that they were related to Melton.
Jenna Paulin Martin, 21, Tiana Maynard, 20, Jevante Price, 20, Michael Montreal Gooden, 21, and Clifton James Roberts, 29, were each arrested on federal kidnapping charges, which carry maximum prison sentences of life without parole.
Tibbs is 5 feet, 7 inches tall and weighs 155 to 165 pounds. It appears from court records and other sources that he has a criminal record in Georgia, according to the station.
"My office will continue to pursue everyone involved with this crime," U.S. Attorney Thomas G. Walker said in a statement Wednesday. "This deliberate attack on our judicial system cannot be tolerated."
Anyone with information on Tibbs' whereabouts is urged to call 1-800-CALL-FBI (1-800-225-5324).
FoxNews.com's Cristina Corbin contributed to this report.