Shaima Alawadi, 32, was taken off life support on Saturday, three days after her 17-year-old daughter found her unconscious in the dining room of their home. Iraqi lawmakers are demanding a thorough investigation.
Police said a threatening note was left near the body. They said the family found a similar note earlier this month, but did not report it to authorities.
"A week ago they left a letter saying, 'This is our country, not yours, you terrorist.' And so my mom ignored that, thinking it was just kids playing around, pranking, and so the day they hit her they left it again and it said the same thing," said Alawadi's daughter Fatima Al Himidi, who said her mother had been severely beaten with a tire iron.
Police said they're investigating the beating death as a possible hate crime, but stressed they're also looking at other possible scenarios. No arrests have been made.
El Cajon Police Chief James Redman said the victim died of severe head trauma but did not confirm the type of weapon. Redman said he was confident it was an isolated incident but would not say why.
It remained unclear whether an autopsy had been completed or when Alawadi's body might be released for the trip to Baghdad.
A family friend said Alawadi's family lived in the house for only a few weeks, after moving from Michigan. Friends and neighbors said Alawadi wore a hijab, the Islamic head scarf.
Alawadi is survived by her husband and five children.
The Associated Press and City News Service contributed to this report.