The witnesses who lived through a mass shooting at a San Diego poolside birthday party over the weekend said Tuesday that they believe race played a role in the attack, disputing early police conclusions. “As additional factors come in, we realize there are multiple components to this problem, but we feel heartbreak in the fact that [police are] trying to dismiss a part of the motive,” said Navy Lt. J.G. Lauren Chapman, who was at the party Sunday evening when 49-year-old Peter Selis opened fire. Selis was white, while most of the victims were people of color. Survivors told reporters that a white man who came to the aid of one black female victim was waved away by Selis, who did not fire at him. San Diego Police Chief Shelley Zimmerman said Monday that she had “zero information” that led her to believe the attack was motivated by race or prejudice. She pointed to the purported shooter’s mental-health fallout after a recent breakup and financial trouble. Selis, who called his ex-girlfriend during the rampage, was fatally shot by police at the scene.