“The pain belongs to all of El Paso,” said Myrna Rider, who described herself as a retired Army wife.

She and Ana Salgado strolled along the memorial site holding placards. “Can I pray for you?” their signs said. People came to them asking for prayers to battle the anger they felt stewing inside of them, to guide them through their hurt. Ms. Rider said she had prayed for the gunman. “We don’t want to be hateful,” she said. “We want to forgive people.”

Memorials erected in the wake of tragedy are often quiet and contemplative. This one, true to the spirit of the border, has sometimes been noisy and lively, with music and children at play, and it has grown startlingly large. The gestures of commemoration stretched the length of a small city block. Dozens of bouquets became hundreds. Flags of the United States, Texas and Mexico fluttered side by side.

On one recent evening, a mariachi band played. Matachines dancers in colorful feathered headdresses performed their bending, rhythmic rituals. A prayer circle, its members clasping rosary beads, recited the Chaplet of the Divine Mercy. (“For the sake of his sorrowful passion, have mercy on us and on the whole world.” )