A Yuma police report includes interviews with the nurse, dentist, anesthesiologist, as well as Zion's mother.
The report indicates Zion needed crowns for a severe case of cavities, and was placed under anesthesia by a Phoenix-based anesthesiologist contracted by Kool Smiles. The dentist told officers the procedure went "well' and lasted for about 35 minutes.
The report notes the anesthesiologist spent 5 minutes in the recovery room before the nurse, and Zion's mother, took over from there.
At one point, the mother and nurse both noticed Zion was not breathing and alerted the anesthesiologist, according to the report.
Zion's mother reportedly told police that while in the recovery room, they had him with machines and it kept beeping and (the nurse) turned it off.
That same nurse told officers she had to keep muting her Oximeter, a device that measures oxygen saturation, because the integrated alarm kept going off, also adding she muted the alarm twice, according to the report.
Finally, the nurse told police that sometimes the Oximeter does not provide an accurate reading as it would on an adult.
Per the police report, staff did perform CPR on Zion, who was taken to Yuma Regional Medical Center, and then flown to Phoenix, where he died on December 20.
According to the police report, Zion's mother told police her son had severe brain damage due to him being out for too long and his brain not receiving any oxygen.
Contacted by Scripps station KNXV in Phoenix about the release of the police report, a company spokesperson released the following statement:
Our heartfelt sympathies continue to be with the family of Zion Gastelum following this very sad and tragic event. The anesthesiologist who rendered treatment Dec. 16 is an independent specialist who contracts with Kool Smiles for procedures involving the use of anesthesia (he is licensed by the AZ State Board of Dental Examiners). He is not currently providing services to Kool Smiles patients. The equipment used by Kool Smiles dentists, anesthesiologists, and staff is medically appropriate for pediatric patients. Kool Smiles continues to investigate the matter. Due to patient privacy laws and out of respect for the family, it would not be appropriate to comment any further.
The Maricopa County Medical Examiner has not yet ruled on a cause and manner of death for Zion Gastelum. Yuma police officials told KNXV their report has been forwarded to the Yuma County Attorney for review.
Francisca Lares, the mother of 4-year old Lizeth Lares, said her child died after a dental procedure in February 2016.
According to the family, Lizeth went into Kool Smiles for dental treatment to deal with an abscess, a tooth was pulled, and then she started showing signs of fever. The family took her back to the dentist the next day, but was sent home, reportedly told that the girl would be fine.
"The allegation in our case is the dentist, Kool Smiles, didn't comply with the standard of care and had they appropriately prescribed some antibiotics, this could have been avoided," said Marco Mercaldo, with the Mercaldo Law Firm in Tucson.
According to court papers, the child died a few days later.
Lares described her daughter as a bright, lively, and very smart young girl loved by her whole family, especially her grandparents.
"She was lovely. She was my mini-me. We all miss her a lot. She took half of my heart with her. They took something from me that will never come back. It is really hard to make peace with it," said Lares.