Christian Moniz Rabino, 28, has been charged with first-degree murder and two counts of child neglect and abuse.

A 28-year-old Las Vegas man has been accused of killing his girlfriend’s 1-year-old son after the child was taken to the hospital last month with trouble breathing, authorities say.

Clark County Detention Center inmate records reviewed by PEOPLE show Christian Moniz Rabino, 28, is currently being held without bond and has been charged with first-degree murder and two counts of child neglect and abuse.

It’s not immediately clear if he has entered a plea or retained an attorney.

Records show Rabino was taken into custody on June 25, almost a month after baby Kai Tesoro, 1, was taken to the hospital, according to local Fox 5 in Las Vegas.

Rabino allegedly told police at the hospital that he called 911 because Kai was “having trouble breathing and ultimately, not breathing,” according to a police report obtained by the outlet.

At the hospital, doctors discovered Kai had “bruising to his head” and “a fracture to his right leg,” according to the report obtained by Fox 5.

Local KLAS reported that one doctor told police the suspected abuse “was one of the worst cases he had seen” as a medical professional.

Fox 5, citing the arrest report, reported that a relative first told police she believed Kai fell off a bed while Rabino was looking after him, but then later said she could not say for certain whether Kai’s injuries were from falling off a bed or from Rabino allegedly abusing the child.

The relative also alleged to police she witnessed Rabino grow frustrated with the 1-year-old child for crying and not being able to walk by himself, according to the police report. The relative reportedly told officers that she witnessed Rabino allegedly shake Kai when he became irritated by the baby’s crying, and that he “plated [him] feet-first on the ground” to try and force him to walk, according to the police report.

Doctors would later determine that action allegedly caused fractures in both of Kai’s legs, the report states.

The family of Kai’s father mourned the 1-year-old’s loss and launched a GoFundMe fundraiser to help pay for the child’s funeral services.

“Our family has always believed Kai would bring a special type of Aloha to this world and those around him,” the GoFundMe post, launched by Kai’s grandfather Steve Tesoro, wrote. “In his passing he fulfilled this belief with the donation of his organs to children in need. Kai is a true hero; his Aloha and spirit will continue to live on. Kai was a joyful and spirited child who brought immense happiness to everyone who knew him, bringing instant smiles to those he met. All he ever wanted was love.”

The family said donations would also go to a fund to help raise Kai’s 3-year-old sister A’leia.

Inmate records show Rabino is set for a preliminary court hearing on Aug. 7.