DENVER — A boy known to his elementary school and to the Department of Human Services went unnoticed for more than seven months before his body was found in a Denver storage unit. His death has child advocates wondering if something in the system needs to change.

Caden McWilliams' principal at Ellis Elementary School in Denver described him as a model student who always had a smile.

Police said they believe he was last seen alive at Ellis Elementary on May 24. 

It's a description that leads Dr. Becky Miller Updike, the executive director of Rocky Mountain Children's Law Center to wonder if administrators and teachers "didn’t know about the red flags" because maybe there weren't any. 

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But the 7-year-old's life at home had warning signs. His mother had a history of substance abuse, and his mother's husband had a history of domestic violence. 

Caden's mother, Elisha Pankey, is being investigated for child abuse resulting in death. 

Although Caden's name is not listed, Human Services was notified the day after he was found dead about a 7-year-old who had died and had involvement with the department. 

"I think this is more of a problem of a kid falling between systems," said Ned Breslin, the CEO of the Tennyson Center for Children. 

Because of privacy laws, schools are not notified when students are a part of child welfare cases. Information is only shared when parents sign a release. 

"What we really need is to be sure someone flags that they are being pulled out of the education system and then who's watching them from there?" said Breslin. 

State Rep. Jonathon Singer said believes there's a way for the education sector and the Department of Human Services to communicate better without breaking the law. The Democrat and former social worker said he wants to update programs so school attendance software can communicate directly with the statewide child protective system. 

“There are certain circumstances where it’s life or limb or where there’s a big indication that it could really be something like that," said Singer. "You know maybe we could get those two systems to talk to each other so the left hand knows what the right hand is doing, and maybe prevent something like this from happening.”

The arrest records are sealed in Caden's McWilliams case, and questions remain about how he died and exactly when.

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