BAKERSFIELD, Calif. -- On Monday, deputies responded to a report of a child not breathing at 711 Tangerine St., in Bakersfield.

Joshua Preston was at the residence with his girlfriend’s five children while she was at work, according to the KCSO.

Preston called 911 to report that he had found 2-year-old Guillermo Alvarez not breathing, police said.

Medical aid personnel arrived and began CPR. Alvarez was taken to Kern Medical Center for treatment.

While he was at KMC, medical staff reported that they found what appeared to be bruising and other possible trauma to Alvarez. Because of the suspicious nature of the injuries, homicide detectives began an investigation, the KCSO reported.

Alvarez was in critical condition and it was determined that he would be transferred to Children's Hospital of Central California in Madera for further treatment.

Once he was at the hospital, he died as a result of his injuries, KCSO reported.

Once the autopsy was completed, it was determined that Alvarez had several injuries consistent with being at the hands of another.

Detectives conducted several interviews.

Detectives also served a search warrant at the residence where Alvarez lived and seized several items from the home.

The four other children that were at the residence were taken into protective custody as a precautionary measure.

They did not appear to have any similar injuries, the KCSO reported.

Thursday, Preston came to the sheriff’s office to meet with detectives.

He was arrested and charged with the killing of Alvarez, along with felony child endangerment.

He was booked on those charges at the Kern County Jail.