It turns out Child Protective Services had been at the family's home before.
CPS on Monday took emergency custody of the boy's two siblings -- a four-year-old sister and an eight-year-old sister.
"I think it's really a shame," said one neighbor.
"I haven't been over here. It's just too sad," said neighbor Daniel Ramirez.
With candles, stuffed animals and toys fresh from the toy box, the memorial is growing at a Pasadena apartment complex as neighbors try to understand what happened to two-year-old baby Steven Drouillard. Police say Steven was found bruised and lying lifeless on the sidewalk wearing a t-shirt and diaper.
"I just come up here and seeing the baby laying there, I was like (gasp); it took my breath away," said neighbor Maryann Wright
Witnesses say they watched as a man performed CPR on the baby boy.
"Going like that on the chest of the baby," said one young witness.
Another witness told us, "And he started throwing up blood."
Pasadena police confirm the toddler had bruises, something neighbors noticed the day before his death.
"He had a bruise on his eye and scratched on his face," said a neighbor who did not want to appear on camera.
CPS says it is speaking with Steven's mother and her boyfriend, but so far the explanation is not consistent with the child's injuries. CPS told us the boy was in the custody of his mother's boyfriend when he died.
"A lot of people have a lot of unanswered questions about what happened to this kid, even though he's not ours," Wright said.
CPS did not go into detail about their previous case with this family.
Family members were in court Monday afternoon to try to get back custody of the boy's two sisters.