Adding to the mystery was the discovery of the skeletal remains of two unidentified people inside the apartment of the shooter, Antonio Pineiro, 48, who died at a hospital Thursday night after being shot by police. The remains are believed to be his parents, who have not been seen by neighbors for more than a year.
"We have not established a motive at this point in time as to why the suspect took this action," Long Beach Police Lt. Bill Blair told a news conference Friday. "Our officers are credited with saving a number of lives by the immediate action they took by intervening in this situation."
Pineiro was shot minutes after he entered the Top Valu Market and opened fire on customers and employees, killing two and wounding four.
"He was calm and quiet," said Conrad Ibasco, who was shopping with his wife, Theresa, and 7-year-old daughter, Barbara, when the shooting started. "He doesn't even say any words. He was determined to kill."
The child, along with the cashier, Marcella Perez, 43, was killed while Ibascos suffered only minor wounds.
"I saw my daughter lying on the ground all bloody. I tried to save them, but it was too late. It all happened so fast," Ibasco told Los Angeles television station KABC as he sat on his sofa with his sedated wife sleeping nearby.
Two other injured people, Richard Cohen and Concepcion Enriquez, were scheduled to be released from an area hospital sometime Friday.
Around 50 people were inside the store when Pineiro entered with a handgun and opened fire. Patrons and employees ran for cover in the rear and tried to stay down until police arrived.
"You could hear gunfire going on in the store and there were panicked shoppers running out and telling the officers the gunman was still inside shooting people," Blair told reporters.
Witnesses said the first two officers on the scene were heard inside ordering the gunman to surrender. The commands were followed moments later by a volley of gunshots.
Late Thursday night, detectives searched Pineiro's apartment, which is located just across an alley from the Top Valu Market. Inside, they found the decomposed remains of two individuals.
Police said it would take some time to identify the bodies, but initial suspicions are they could be the remains of Pineiro's parents. Neighbors said they were told that the couple had moved back to their native Cuba and that they had not noticed any strong odors coming from Pineiro's apartment.
"It was clear the bodies were more than a year old," said Blair.