Max Shacknai, 6, died Sunday from injuries he sustained in a fall last week at the Coronado mansion.
Two days after the boy's fall, the nude body of his father's girlfriend, 32-year-old Rebecca Zahau, was found at the mansion hanging from a balcony with a rope around her neck and her hands and feet bound.
Zahau was reportedly looking after the boy when he fell.
Newly-released police reports show that the parents of the boy, Jonah Shacknai and his ex-wife, Dina, were involved in at least two domestic altercations. The incidents happened in 2008 and 2009, and no one was arrested.
Investigators say the son's death was an accident, but Zahau's death is suspicious. Suicide has not yet been ruled out.
Authorities repeated Monday they haven't established any link between the boy's fall and the woman's death.
Jonah Shacknai founded Medicis Pharmaceuticals Corp. and has been chairman and chief executive of the Scottsdale, Ariz.-based company since 1988.
The Associated Press contributed to this story.