Hector Mendoza is the oldest son of Carmen Mendoza and the brother of honor student Paco Mendoza. They played at their father's barber shop until he died and the place was sold. While there, they met Isaiah Morris and twins Naomi and Ty Johnson, whom the brothers befriended enough to know in their childhood because the three kids played in the park across from the Mendoza family barber shop.
Hector and Paco were isolated by local lone gangster Felix Aguilar and threatened into being his "crew", ripping the brothers away from the three kids and making them all grow distant as they grew older. One fatal night years later on that same block, Aguilar was with the brothers and saw the Johnson twins and Isaiah, deciding he wanted to pick a fight. Aguilar pressured the brothers to join him in insulting the three best friends, but the Johnsons and Isaiah resisted with their own resolve. Naomi was the most fearless, and it only became worse when Aguilar hallucinated everyone insulting him or trying to talk him down from his anger when he didn't want to be, which he saw as degrading to his manhood.
Aguilar pulled a gun on Naomi to everyone else's horror, except for hers since she still wasn't scared. Then when he pretended he was only joking, he suddenly shot Naomi in her stomach, then forced Paco to make the two boys kneel on the blacktop and then shoot them point blank in their heads, threatening Paco violently if he didn't follow Aguilar's orders. Hector and Paco were both shaken and riddled with guilt, but they obeyed Aguilar's demands to hide the gun, which they put in their father's ashes. Naomi would be found clinging to life and end up dying at the hospital after giving her statement.
Sketches from witnesses at the scene led them to Paco and Hector. Paco owned up to everything out of fear of Aguilar and to protect his family, despite risks of the death penalty and his chances of his success as an honor student being ruined. Hector stepped up, especially after the gun was found, and he told the truth about everything, how Paco only shot the two boys and they all left the three kids to die because Aguilar forced and scared them to.
Aguilar was captured after a chase and violent standoff, then legally tricked into confessing. Hector and Paco received reduced sentences of prison time for their testimonies to get Aguilar convicted. (CI: "Senseless")