The situation unfolded near 9th Street and Azusa Avenue around 7 a.m. when a woman called 911.
Authorities said the woman, who is the 39-year-old suspect's ex-girlfriend, was assaulted but was able to get out of the apartment. She was transported to a hospital with unspecified injuries.
The suspect was identified as Ricardo Barrios of Azusa.
Authorities said two children, a 12-year-old boy and a 17-month-old girl, were held inside the apartment until Barrios released them at about 11:45 a.m. The infant is the woman's daughter, police said.
"I come out back and there's these officers that have really big assault rifles," said neighbor Gyasi Howard.
"He's a nice guy and everything," Howard said of the suspect, "but they obviously drink a lot. They have some situations every now and then. We didn't think it was anything that serious or anything that bad until this situation happened."
Los Angeles County Sheriff's Department Special Enforcement Bureau officials and crisis negotiators were in communication with the suspect over the phone during the standoff.
Barrios eventually surrendered shortly after 12:30 p.m. and was taken into custody without incident, according to the Los Angeles County Sheriff's Department. He was taken to the Azusa Police Department and booked on multiple felony charges.
Investigators said no weapons were found inside the apartment.
Some nearby homes were evacuated during the barricade. Azusa police said there was no threat to the broader community but asked residents to stay inside, away from doors and windows, as a precaution.
"When we can resolve a situation with a limited amount of force, it's always a great outcome," said police Officer Mike Bires.
Anyone with information about the incident is asked to call Azusa police at (626) 812-3200.
Note: In an earlier report, it was said the children were 16 months old and 11 years old. That information was later updated.