She was still trying to figure out what had happened when she said she got a call from her father, who was at the hospital with Paul, the baby. Her father told her that she needed to get in touch with Jordan’s parents right away.

“She’s gone,” Ms. Anchondo told them. “She’s gone.”

She hung up and rushed to a family reunification center, where she said their family waited hours without any news about her brother.

The family feared that Skylin was also missing, but then learned that she had been taken to her cheerleading coach’s house, and was having an impromptu birthday party there. Ms. Grijalva said she and her family dressed the little girl in a yellow dress and painted her nails to match. They made spaghetti and bought a chocolate cake. “We yelled ‘surprise,’” her coach recalled. “We threw up the balloons.”

It was the last bit of normalcy, they knew, that the girl would have. Soon, her grandparents — Jordan’s parents — called and came to pick her up. Her grandmother started crying when she saw the girl, according to Ms. Grijalva.

“‘My daughter is dead,’” Ms. Grijalva recalled her saying as if in a trance. “‘Pray for Andre, they still haven’t found him.’”

Ms. Anchondo slept at the hospital that night with her nephew, baby Paul, she recalled. They still hadn’t heard from her brother. Even then, she was replaying in her mind the many things the siblings had shared over the years. How he had mispronounced the word “love” when he was little, and for years afterward told her “I ‘ya’ you” instead. How, at 7 years old, he had started his first business, buying lollipops from Sam’s Club and reselling them for $1 each. How he once had walked into a T-Mobile store to buy a cellphone, met a girl there and vowed to marry her — and did, in a courthouse wedding last year.

Ms. Anchondo and her family waited through the night, and most of the next day. It wasn’t until Sunday afternoon, more than 24 hours after the shooting, that they got official confirmation: Andre had been killed.