Police say the 22-month-old boy suffered liquid burns, went untreated and died from infection and sepsis.

MESA, Ariz. — A Mesa mother and her boyfriend face murder and child abuse charges after police said her 22-month-old son suffered severe liquid burns, went without medical care for days and died April 12 at a hospital.

The case has moved from an emergency call at a home near Mesa Drive and McKellips Road to a Maricopa County murder prosecution. Investigators say Artnesia Aaliyah Baptist, 24, and Alexsander Byrne, 21, concealed the boy’s injuries, treated him at home and feared state child welfare involvement before the child died.

Police said officers were called just after 9 a.m. April 12 for a report that a child was not breathing. Mesa Fire and Medical personnel also responded, and the boy was taken to a local hospital, where he was pronounced dead. The first medical findings changed the case quickly. Officers saw injuries consistent with burns, and detectives began trying to account for the days before the emergency call. “Upon arrival, officers located a 22-month-old child unresponsive and suffering from physical injuries consistent with burns,” Mesa police said in a statement reported by local outlets. Court records later described burns across a large part of the child’s body, with investigators saying the injuries appeared to have been caused by hot liquid.

The probable cause account said the burns happened April 3, nine days before the child died. Investigators said the pattern was consistent with hot or boiling water poured over the child’s head and running down his neck, shoulders, chest, back and hips. Police said about 40% of the boy’s body was burned. Byrne allegedly told police he saw “big chunks” of skin peeling from the child during a diaper change. Detectives said Baptist and Byrne denied knowing how the burns happened, but both were the adults responsible for the boy’s care during the period investigators examined. Authorities also said the couple hid the injuries from the child’s biological father and threatened to kill him if he came to pick up the boy after the burns but before the child died.

Investigators said the child’s condition worsened while he stayed inside the home. Court records say the couple used burn cream, Tylenol and aloe vera instead of taking him to a hospital. Byrne allegedly told police the boy developed a fever, began vomiting and could not walk after he was burned. Detectives also reviewed internet searches tied to Byrne’s accounts, including searches about burn cream, first-degree burns and whether second-degree burns can kill a person. Police said Baptist and Byrne told Byrne’s parents the child had a cold. When Byrne’s mother offered to take the boy to urgent care, investigators said, the couple said he was improving. The medical examiner later linked the death to a severe infection and sepsis.

The case also drew attention to earlier contact with the Arizona Department of Child Safety. The agency told ABC15 there had been two prior reports involving Baptist within the previous year. One report in May 2025 alleged Baptist abused another child, but DCS said the allegation was unsubstantiated. A later report in September involved alleged neglect after a domestic violence incident between Baptist and the toddler’s biological father. DCS said it investigated with law enforcement and found no evidence to support that allegation. The agency assessed the boy as safe after Baptist moved out with him and his siblings. That assessment came about seven months before the boy’s death.

Byrne later gave police a recorded post-Miranda statement, according to court paperwork. Investigators said he admitted the child did not get medical care because he believed Child Protective Services would become involved. The paperwork said Byrne admitted he knew refusing care was wrong and illegal, caused more injury and pain, and caused the boy’s death. Police arrested Baptist and Byrne on May 26. They were accused of first-degree murder and child abuse likely to cause death. A state fatality summary later said both were indicted May 29 on one count of first-degree murder and one count of child abuse. Court records cited by local reports said each was held on a $1 million cash-only bond.

The medical details in court records describe a decline that prosecutors are expected to use as a central part of the case. The affidavit said infection spread before the child died and that the medical examiner described the final period as a slow and painful decline from sepsis that had been underway for at least 48 hours. The same document said the odor of the child’s infected skin filled the emergency room. It described missing, red and infected skin on the shoulders, clavicle, sternum, under the hair, along the back of the neck, and down the back, buttocks and hips. Those descriptions appear in court filings and police summaries, not in a trial finding.

The case remains in the early criminal stage, and Baptist and Byrne are presumed innocent unless convicted. The allegations now turn on medical findings, digital records, the timing of care decisions and statements made to relatives, police and the child’s biological father. Prosecutors must prove not only how the burns happened but also what each defendant knew and did afterward. The dependency side of the case also moved forward, with DCS saying siblings were placed with an unlicensed caregiver and that the agency was providing services to the family. No trial date has been publicly detailed in the available reports.

For now, the case stands as a Maricopa County prosecution built around a nine-day gap between an alleged burn injury and a 9 a.m. emergency call. The next major public steps are expected in Superior Court as Baptist and Byrne answer the indictment.

Author note: Last updated June 23, 2026.