Abdullah says her son took part in protests to demand equality and greater rights. Among the charges he faced were throwing rocks at police and firing on a police checkpoint. She says her son denies the charge of firing on police.
Scholars of Islamic law, or Shariah, hold vastly different views on the application of the death penalty. Under the kingdom's interpretation of Shariah, judges have wide discretion to rule and hand down death sentences for lethal as well as non-lethal offenses.
The kingdom has one of the highest rates of execution in the world. Last year, 47 people were executed on one day, including a prominent Saudi Shiite cleric convicted for his role in violent protests. The cleric, Nimr al-Nimr, denied the charges of sedition. His supporters say he was punished for being an outspoken government critic and a key leader of the Shiite protests in eastern Saudi Arabia in 2011 and 2012.
The group of 14 were charged for their role in those same protests.
Reprieve, an advocacy group that opposes the death penalty, said it has established that at least one of the defendants was never permitted to see a lawyer. In al-Adam's case, no evidence against him was presented at trial, said Reprieve.
Activists say there is growing cause for concern after the kingdom executed four Shiites in July convicted on charges of terrorism for their role in the same protests and violence with security forces.
On Friday, 10 Nobel Peace Prize winners appealed to King Salman and his son, the crown prince, to halt the executions.
Human Rights Watch says that if Saudi Arabia's new leadership is serious about reform, "they should immediately step in to stop these executions." In a joint statement, Human Rights Watch and Amnesty International said the rise in death sentences against Shiites in Saudi Arabia "is alarming and suggests that the authorities are using the death penalty to settle scores and crush dissent under the guise of combating 'terrorism.'"