So Maribel Rodriguez went on national television to say she was sorry.
"I had to make my apologies to these people," she said.
But Robert Hawkins' mother says she knows there is only so much her apologies can do to make up for what her son did Dec. 5.
The 19-year-old opened fire inside the Von Maur department store with an AK-47, striking 11 people. Six died where they fell, one died on the way to a hospital and another died at a hospital. Three other people were wounded, two seriously.
"I can't bring any of these beautiful people back," Rodriguez said.
Maribel Rodriguez sobbed after watching her interview on ABC's "Good Morning America" Thursday morning because that was the first time she had seen pictures of the eight people her son killed last week.
Rodriguez told The Associated Press that she has been devastated since her son opened fire at Westroads Mall.
The 41-year-old said she sought psychiatric treatment last Thursday. She said she checked herself out of the hospital to plan Hawkins' funeral and bury her son on Tuesday. She did not say where she received treatment.
"I would never want for anyone to do what I have done these last couple days," Rodriguez said.
On the night before the shootings, Rodriguez made dinner for Hawkins and two of her daughters at the house of one of her ex-husbands - Hawkins' stepfather. The stepfather, Mark Dotson, was vacationing in Thailand.
She and police have said Hawkins took the assault rifle he used in the shootings from his stepfather's closet.
Dotson said he left a black AK-47-style rifle in the closet so that his ex-wife could protect herself and the girls against intruders, reports the Omaha World-Tribune.
The couple divorced 11 years ago, he said, but had sustained a relationship for the sake of their children.
Hawkins was a troubled teenager who spent four years as a ward of the state after threatening to kill his stepmother in 2002. During that time, he spent about two years in a series of treatment centers, about a year in a foster home before moving back in with his father.
Hawkins had left his father's home some time ago. At the time of the shootings, he was living with Debora Maruca-Kovac and her husband, whose sons were friends with Hawkins, Maruca-Kovac has said. He had lived there for a little more than a year.
When asked what people should think of her son, Rodriguez said: "I'm not perfect, I know that. But you tell me: What could I have done differently? I did my best."