Alice Williams, 37, and her son were cleaning the home when they began fighting, police said. Tristan Williams, 18, stabbed his mother several times with kitchen knives, investigators said.
Arnetta Yardbourgh, who lives at the home, saw the stabbing and called authorities, said police spokeswoman Pat Whitty.
Yardbourgh and O'Neal have a 7-year-old daughter from a previous relationship. O'Neal's agent, Michael Parris, said the girl wasn't at the home.
O'Neal was in Minneapolis, where Los Angeles beat the Timberwolves 97-88 on Friday night in Game 1 of the Western Conference finals. He declined after the game to answer questions about the stabbing.
"He's shook up," said Michael Parris, O'Neal's business manager.
Earlier in a statement, Parris said: "Shaquille is thankful that neither his daughter nor her mother were harmed, and he sends his prayers and condolences to the
The Lakers' center also has three children with his wife, Shaunie.