The barricade situation began shortly after 8 a.m. at a single-story home near the intersection of West 20th Street and South Mariposa Avenue, a Los Angeles Police Department spokesperson said.
Responding officers found the victim suffering from at least one blow to the head with an aluminum bat, the LAPD said. She was transported to Cedars-Sinai Medical Center, where she was pronounced dead. Her identity was not immediately released.
Several nearby homes were evacuated during the standoff with the suspect, and news video from the scene showed multiple armored vehicles and heavily armed SWAT officers at the scene.
Police held an impromptu news conference at the scene, where they identified the alleged assailant as 35-year-old Joshua Ramos, a resident of the home.
Shortly before 2 p.m., the LAPD announced that Ramos was in custody.