SAN MARCOS, Calif. - Authorities Tuesday arrested a man in connection with the death of a woman in a San Marcos apartment.

According to authorities, an unidentified 41-year-old woman was found dead and an 8-year-old girl badly wounded at about 3:30 a.m. Tuesday at an apartment complex in the 400 block of North Twin Oaks Valley Road.

Deputies investigated, and then called in homicide detectives as the wounded child was being transported to Rady Children's Hospital.

The girl was admitted to the trauma center in critical condition and underwent surgery. 10News learned the girl is now in stable condition.

Later in the afternoon, authorities arrested 28-year-old Daniel Hernandez in connection with the woman's death and the assault of the young girl. He was arrested outside of a Vista apartment complex.

Authorities said Hernandez had a platonic friendship with the deceased woman.

A man -- a relative of the victims -- told authorities he called 911 and reported the apparent homicide and attempted murder.