Michael Bargo, the man convicted of being the mastermind behind the brutal killing of a 15-year-old Marion County boy, has been sentenced to death.

Bargo had no reaction when Judge David Eddy sentenced him to death.  Judge Eddy called it the most cold, calculated and premeditated murder he has seen in his 32 years of law.

"I reference my experience only to note this is the most cold, calculated and premeditated case of murder I have ever seen," said Eddy.

One of Bargo's relatives wept openly upon hearing the sentence.

In August, a 12-member jury found Michael Bargo, 21, guilty of first-degree murder for his role in the 2011 slaying of 15-year-old Seath Jackson and recommended that he receive the death penalty.

Bargo was the only one sentenced to death of the five people charged and convicted in the case. Charlie Ely, Justin Soto, and siblings Kyle Hooper and Amber Wright all received life sentences without the possibility of parole for their roles in Jackson's murder.

A sixth person, James Havens, was charged with accessory to murder after the fact.

"Those people were victims and the system totally let them down and put them into a position to take matters into their own hands, which they should not have. If the parents had been there, if they had done more, this would not have happened," said Bargo's attorney, Candace Hawthorne.

Prosecutors said they lured Jackson to a home in Summerfield in 2011. That is where they beat and shot him to death. They dismembered and burned his remains. Then, hid them in multiple paint cans and threw them in a rock quarry. 

Bargo is now the youngest inmate on death row in Florida.

According to the Florida Department of Corrections' Death Row Roster, the state's youngest death row inmate before Bargo was 22-year-old Terrance Phillips, who was sentenced last year for two deadly shootings in Jacksonville on Christmas Eve in 2009.

It is a fact which may become part of his appeal.

Defense attorneys plan to argue Bargo's brain wasn't fully formed when he was 18 years old at the time of the murder. They will also point out that two jurors did not recommend the death penalty.