As reported by the San Diego Union-Tribune:
Darren Chaker, 37, was visiting his girlfriend at the multiunit apartment complex when he heard screams for help and called authorities.
He flagged down an officer outside and they both went to the building, where they found the woman standing in the hallway wearing a white nightgown covered in blood. Her son was standing behind her, Chaker said.
The officer asked, “Who did this?” The woman pointed at her son and the officer handcuffed him, Chaker said.
The man said, “Yeah, I did it,” Chaker said. The mother was crying and asking, “Why? Why did you do this?” and the son answered, “Because he's an (expletive),” Chaker said. The man was wearing only blue boxer shorts and appeared enraged but not under the influence of anything, Chaker said. The witness said the woman's screams were echoing through the hallway, but no one came out or opened a door. See link for entire article: