TALLAHASSEE, Fla. -

Weighing whether execution is a "proportionate" penalty, the Florida Supreme Court on Thursday overturned a death sentence for a man convicted in the 2008 murder of a Jacksonville convenience-store worker.

Justices, in a 5-2 opinion, found that Michael Yacob should serve life in prison instead of facing lethal injection in the shooting death of 19-year-old Moussa Maida (pictured below).

Yacob, now 28, killed Maida during a robbery of a family-owned convenience store. Maida handed over money to Yacob but then flipped a switch that locked the store's front door, temporarily preventing Yacob from escaping, the court opinion said.

Yacob shot through the glass of a cashier's booth, hitting Maida in the chest, and then was able to flee the store after pulling apart burglar bars.

The Supreme Court's ruling focused on what are known in death penalty cases as "aggravators" -- factors used in determining whether execution is warranted. The majority opinion said the case involved a "robbery gone bad" and that there were not enough aggravating factors to impose the death penalty.

READ THE RULING: Michael Yacob vs. State of Florida

"The evidence shows that although Yacob held a gun on Maida while in the cashier's booth, he pocketed it as he left the booth and continued walking toward the front door despite seeing Maida stand up inside the cashier's booth,'' the majority opinion said. "Perceiving Maida's sudden movement first to the counter and then toward the booth door as a threat to the completion of the robbery and his escape, however, Yacob immediately pulled out the gun, ran back to the booth door, and shot twice, killing Maida with the second shot. There was no indication that murdering Maida was part of Yacob's original robbery plan."

Justices Barbara Pariente, R. Fred Lewis, Peggy Quince, Jorge Labarga and James E.C. Perry agreed to overturn the death sentence. Chief Justice Ricky Polston and Justice Charles Canady were in the minority.

"I dissent from the majority's decision to reverse the death sentence imposed on Yacob, which is in derogation of the unequivocal provision adopted by the people of Florida to constrain the power of this court to set aside sentences of death,'' Canady wrote.