Family and friends were distraught at a court hearing Monday, weeks after Jaxon was found unresponsive and injured in his crib on Easter Sunday. Jaxon's cause of death is still under investigation after passing away in the hospital days later.
"I can't imagine what this sweet little baby went through," Evangeline Dominguez-Estrada said. "Who can hear a baby crying and continue to harm them, let alone kill them?"
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Police say Jaxon's then-17-year-old foster brother, his cousin, had sexually and physically abused the toddler, leading to several suspicious traumatic injuries.
"He was only two, and he did not deserve this," Dominguez-Estrada said.
Monday morning, the suspect was formally charged with murder, as well as multiple other felonies, including child assault causing death and sexual assault.
"This was a 2-year-old child who was horribly abused and viciously murdered," Rosen said. "And we want to make sure that the level of accountability is the right level."
Evidence suggests that Jaxon had been repeatedly sexually and physically abused by his cousin after being placed with the family by the county in February.
Our partners at the Mercury News report the cousin's mother also had a previous conviction of felony child endangerment in 2014 - a crime that should have disqualified her from being a foster parent.
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County Spokesperson Peter Gallotta told ABC7 Eyewitness News in a statement the Department of Family and Children Services is conducting its own investigation while requesting that the California Department of Social Services do the same.
Gallotta added, "The county is committed to swiftly investigating every aspect of this horrific tragedy and publicly sharing the results of these investigations when available and to the extent allowable by law."
DA Rosen says he will investigate whether or not anyone else is responsible for Jaxon's death, even the county he represents.
"This is the third child in the past couple of years under the care and custody of the Department of Family and Children Services who has been murdered," Rosen said. "Change needs to come, and it needs to come fast - and it needs to happen now."
The suspect has since turned 18, and Santa Clara County District Attorney Jeff Rosen is seeking to try him as an adult.
The suspect in this case will be back in court on May 21.
At that time, the probation department will make its recommendations on whether this case should be tried in adult court.