"My son was so wonderful. He was such a joyful kid," says Le.
Fox died Friday, at the hospital after police received a call to the boy's home in Garden Grove.
"When the officers arrived, they found a 2-year-old, with his face covered in blood," said Lt. Travis Whitman, Garden Grove Police Department.
The exact cause of death has not yet been released, but police arrested 27-year-old Lae Thongphun for child abuse. He is the boyfriend of the child's mother, who investigators allege was caring for him at the time.
Police say the boy's mother Marykay Concepcion is also under investigation.
She had full custody. Le had visitation rights.
He says he noticed bruises on his son before, but could never get a straight answer.
"Yeah, he would always just say that he fell," says Le.
Le's 4-year-old daughter is now in protective custody.
As he prepares to bury his son, he worries how he will pay for his funeral.
"I just hope justice prevails," says Le.
Thongphun remains in custody, his bail set at $1 million.