SAN JOSE — A Santa Clara County jury Tuesday convicted three gang members in connection with the 2012 killing of a 14-year-old boy who was stomped to death on a Roosevelt Park basketball court by a mob that accused him of being affiliated with a rival gang.

The victim, Heriberto Reyes was an eighth-grader at Bernal Intermediate School in South San Jose and did not belong to a gang. His older brother, Juan Reyes, was also badly beaten but survived.

After a 10-week trial and about four days of deliberation, the jury convicted Jacob Lynch, now 20, and Clemente Salas, 19, of first-degree murder with the special circumstance of murder for the benefit of a street gang. They each face life in prison without the possibility of parole.

However, the jury found a third young man, Scott Conway, 22, who was represented by defense attorney Ed Fernandez, not guilty of murder. Conway was found guilty of beating up Juan Reyes, and of two previous separate assaults on young boys who were not in a gang. He faces a maximum of 23 years in prison.

Superior Court Judge Vanessa A. Zecher set sentencing for Oct. 9.

Prosecutor Carlos Vega said Tuesday that Conway had become a member of the Roosevelt Locos gang and was trying to prove himself through the attacks.

“Heriberto was a 14-year-old little boy who had finally gotten old enough to play basketball with his older brother,” Vega said. “He was a victim of absolutely senseless gang violence.”

Five other young men were charged in the April 27, 2012, killing. Two cooperated with Vega’s office; one faces a 13-year sentence; the other, 22 years. Two pleaded guilty to manslaughter and face 16 years each.

When Heriberto and a friend walked onto the courts, they were confronted by several people who started pulling up the boy’s shirt to look for gang tattoos, Vega said.

“Then, despite Heriberto’s protests that he was not affiliated with any gang, they savagely attacked him, stomping repeatedly on his head,” Vega said.

Heriberto’s brother rushed to his aid but was attacked and knocked unconscious. Others who tried to intervene were told they would also be assaulted if they got involved.

Heriberto died from massive head injuries three days later at Regional Medical Center.

“There is a sad misconception that gang members only terrorize and target other gang members,” Vega said. “Heriberto’s death is a tragic example of how criminal gangs threaten us all.”

Contact Tracey Kaplan at 408-278-3482. Follow her at Twitter.com/tkaplanreport.