A Suffolk Superior Court jury this morning convicted the last of four defendants charged in a botched kidnapping ploy that nearly killed an Allston man two summers ago, District Attorney Daniel F. Conley said.

Jurors found TYON FEASTER (D.O.B. 7/31/84) of Cambridge guilty of kidnapping with intent to commit extortion, aggravated assault and battery with a dangerous weapon, and attempted murder. The verdict came one day after the convictions of Feaster’s two male co-defendants, JOSEPH CALDWELL (D.O.B. 12/5/82) of Mattapan and DOMONIC CAMPBELL (D.O.B. 4/15/88) of Cambridge, and their femme fatale associate, JILLIAN JACQUES (D.O.B. 3/31/85) of Allston.

“This was a chilling plot by four individuals who were willing to kidnap, beat, and torture a man, first for drugs and then for money,” Conley said. “It was a living nightmare, not just for the victim but for his family, who listened to him pleading for his life in a ransom call.”

The trial was prosecuted by Assistant District Attorney Jeremy Bucci, chief of Conley’s Narcotics Unit, and Assistant District Attorney Joseph Ditkoff, deputy chief legal counsel to the Suffolk DA’s office. Over the course of two weeks, they elicited testimony from more than two dozen witnesses and introduced evidence proving that the foursome planned to ransom a small-time drug dealer for large quantities of marijuana on the morning of June 1, 2008.

Evidence proved that Jacques arranged to buy a small amount of marijuana from the 24-year-old victim on June 1, 2008, but insisted that the transaction take place in her Glenville Avenue apartment instead of the lobby of her building as she had in the past.

Evidence also showed that Caldwell, Campbell, and Feaster were lying in wait for the victim inside Jacques’ apartment. They took his cell phone and tied him to a chair. They demanded that he procure large quantities of marijuana for them – a feat the victim said he could not accomplish.

In the hours that followed, the victim was repeatedly beaten by his assailants, who began to demand cash when it became clear the victim had no access to more drugs. They threatened him with death and mutilation and, in phone calls to his brother, promised to shoot the victim in the head if they were not given $5,000.

The victim’s brother raised a little over $4,000 and, after notifying Boston Police, provided it to two women at Dudley Station who had been sent by the kidnappers. Those women were apprehended; further investigation showed that they were unaware of their true role in the ransom scheme.

Jacques left the apartment that afternoon to go to work. At about 11:00 that evening, members of the Boston Fire Department responded to an alarm at her building. On gaining access to her apartment, they found that a pillow and several rolls of toilet paper had been set on fire before sprinklers doused most of the flames.

Boston firefighters also found the victim tied to a chair, having been left to die in the blaze. He had been severely beaten and was bleeding from his eyes. Injuries to the man’s face were so severe that he was not immediately able to view photo arrays because his eyes were swollen shut.

Caldwell, Campbell, Feaster, and Jacques were represented by attorneys Tonomey Coleman, Robert Griffin, Pamela Harris Daley, and Joseph Hennessey, respectively.

Superior Court Judge Frank Gaziano will sentence the defendants on May 5. Each faces up to life in prison.