Shia Sheikh Al-Nimr Among 47 Executed by Saudi Arabia

Since King Salman took to the throne last January, executions have nearly doubled prior to the previous year. Mass condemnations have spread throughout the Middle East in response to Saudi Arabia’s latest and largest execution in decades, which killed 45 Saudis, a Chadian and an Egyptian. Among those executed were Shiite activists and Sunni members that were allegedly associated with Al Qaeda. The ministry reports that many were beheaded and others were shot via a firing squad.
One of the Saudi men executed was a Shia Cleric, Nimr al-Nimr, a prominent vocalist and activist for the marginalization of Shiites and anti-government protests. Sheikh Nimr established a large following among young Shites who experienced marginalization by Saudi Arabia.
Many have argued that sectarianism was the reason for the killings, however, according to Saudi Arabian officials, these executions were in regards to Al Qaeda attacks in 2003 and 2004 that killed Saudis and foreigners. The 2003 attack that killed 9 Americans and 35 people, occurred in the immigrant compounds of Riyadh. The 2004 attack, killed 22 people and occurred in Khobar.
According to the New York Times and an Associated Press Reporting:

“On Saturday, some Saudis, including journalists at a government news conference, thanked their leaders for carrying out the death sentences. The country’s top cleric, Grand Mufti Sheikh Abdulaziz Al Sheikh, called them a ‘mercy to the prisoners’ because the executions would save them from committing more evil acts.”

Al Sheikh believes that by that executing the prisoners will save them from committing more evil acts. However, where in the Quran does it say we should kill people to stop them from committing evil acts? Why is Saudi playing God? Why were these 47 individuals really killed? Was it based primarily off their affiliations with Al Qaeda? Or is it deeper than that?