Police say a 4-year-old was left at an apartment for discipline that became deadly.

AURORA, Colo. — A 24-year-old Aurora man is charged with first-degree murder after police said he beat a 4-year-old boy who had been brought to his apartment for a so-called “boot camp” to correct behavior.

The case now reaches beyond the man accused of striking the child. Police also arrested the boy’s mother, 23-year-old Destini Rose Lipsky, after investigators said she left her son with Alexander Martinez-Armstrong and gave him permission to discipline the child. The boy, who has not been publicly identified by police, died after officers and paramedics responded to a report that he was unconscious and not breathing.

The emergency call came around 10 p.m. May 16 from an apartment in the 14100 block of East Tennessee Avenue, police said. Officers found the child with major injuries and had him taken to a hospital, where he died. Martinez-Armstrong, who police said was not the boy’s father, was interviewed at the scene and later arrested. Aurora police said he acknowledged striking the child. Investigators described the apartment as the place where the boy had been staying under an informal discipline plan. The plan, according to police accounts of interviews and records, was meant to address acts such as sneaking candy, getting into his mother’s purse, lying and not listening.

Police said the child had bruises across his body when first responders arrived. Court details reported from the arrest affidavit said some marks appeared to be in different stages of healing and shaped like injuries that could come from a belt or similar object. Martinez-Armstrong’s girlfriend told investigators she heard the boy crying and screaming from another room while he was forced to write numbers and perform exercises, according to reports describing the affidavit. Police said Martinez-Armstrong admitted striking the boy repeatedly. A reported affidavit account said he struck the boy at least 21 times with a belt on the day the child died. The official cause and manner of death were expected from the Arapahoe County Coroner’s Office.

The investigation shifted days later to Lipsky. Aurora police said she was arrested May 22 in Colorado Springs after further work by investigators. She faces a charge of child abuse resulting in death. Police said Martinez-Armstrong had been acting as the child’s caretaker at the time of the fatal injuries. Reports citing the affidavit said Lipsky described Martinez-Armstrong as close to her, like a brother, and identified him as the child’s godfather. Investigators said she had turned to him because she wanted stricter discipline for the boy. Police have not said that the boy’s father was charged in the case, and Martinez-Armstrong was identified by authorities as someone other than the father.

The “boot camp” description has become central to the case because investigators say it was not a licensed program, school or state-supervised placement. It was a private arrangement inside an apartment. The alleged punishments described by investigators included whippings, spanking, push-ups, planks and wall-sits. Reports citing court documents said Lipsky told investigators she had used some of the same punishments on the child and allowed Martinez-Armstrong to use them as well. The boy’s alleged behavior, as described in the affidavit, involved common preschool conduct: lying, not listening, taking candy and reaching into a purse. Investigators now say the response to that conduct led to fatal violence.

Martinez-Armstrong was booked on a first-degree murder charge and held without bond in Arapahoe County. Lipsky was held on a $500,000 bond while awaiting transfer to Arapahoe County after her arrest in Colorado Springs, according to police and local reports. It was not immediately clear from public reports whether either defendant had entered a plea. Prosecutors are expected to rely on police interviews, medical findings, witness statements and the reported condition of the child’s body. The coroner’s final findings will be important because they can establish the injuries that caused death and whether older injuries support a broader pattern alleged by investigators.

The case began as a medical emergency and became a homicide investigation within hours. Police said responding officers saw enough injury to call in the Major Crime Homicide Unit. The East Tennessee Avenue apartment sits in a residential part of Aurora near several apartment complexes and busy roads. By the next day, police had announced Martinez-Armstrong’s arrest. Less than a week later, they announced Lipsky’s arrest. Authorities have released limited details about the child himself, and police have not publicly named him. That has left the public record focused on the adults, the alleged discipline plan and the evidence gathered after the 911 call.

Investigators said one witness, Martinez-Armstrong’s girlfriend, gave an account of what she heard and saw inside the apartment. Her reported statement placed the child in the living room during punishment and described screams while Martinez-Armstrong used a belt. That account may become a key part of the case if prosecutors bring it into court. Police also cited Martinez-Armstrong’s own statements after the child died. In early public statements, Aurora police said only that the boy had significant injuries and that Martinez-Armstrong admitted striking him. Later reporting from court records added details about the alleged belt strikes, exercises and permission from the mother.

The next public milestones are expected in Arapahoe County court, where the murder and child abuse cases will move through advisements, bond hearings and possible preliminary hearings. As of June 18, police had announced two arrests, and the coroner’s final public report remained a key pending record.

Author note: Last updated June 18, 2026.