The suspect, 32-year-old Ethan Nieneker, allegedly first shot Hector Leopoldo Martinez Machuca, a Target employee, as he was collecting carts in the parking lot on Monday afternoon, Austin Police Sgt. Nathan Sexton said at a news conference on Tuesday.
Nieneker then allegedly approached a family's car, fatally shot the little girl and her grandfather, Adam Chow, and minorly wounded Adam Chow's wife and stole their car, Sexton said.
Austin Police Chief Lisa Davis called it an "unprovoked and deliberate attack" on "innocent lives," adding that it was "in broad daylight."
Asked if the suspect gave a motive, Sexton said, "He said that he was Jesus and there was really no reason whatsoever given. It was a completely random choosing of the victims."
Astrid, who referred to her grandfather as "GongGong," was "pure silliness and joy. She loved singing, dancing, and making us laugh," the family said. "We are broken and miss them both so much."
After the shooting, Nieneker allegedly fled the scene in the stolen car and carried out other crimes, including "causing multiple crashes," "assaulting another female driver and stealing her Volkswagen," trying to break into a Waymo vehicle and vandalizing the home of an acquaintance from bible study, Sexton said.
Officers found Nieneker naked; they subdued him with a Taser and took him into custody, police said.
Nieneker, who worked at a restaurant and lived alone, has a history with the Austin Police Department, including assault, driving while intoxicated and mental health reports, Davis said.
Davis did not elaborate on the mental health issues but said, "This man had some serious issues," adding, "There were some serious failures here."
Nieneker faces charges including two counts of capital murder and one count of first-degree felony murder, Sexton said.
The suspect's gun "was acquired through family," Sexton said.
A Target spokesperson said in a statement on Monday, "We are devastated by the violence that occurred today."
"Our hearts are with the families and loved ones of those who lost their lives, our team in Austin and all those impacted by this tragedy," the statement said. "We are working with law enforcement as they conduct their investigation and are grateful to the first responders who acted quickly at the scene. In the days ahead, we will continue partnering with law enforcement and will be providing support resources, including grief counseling, to our team."
Austin-Travis County EMS had initially reported four victims, but that number was later corrected.
