The woman, whose name has not been released, suffered a fractured skull when she was beaten about the head with the skateboard
between the 7-Eleven store and a community church near Mission and Niles boulevards.
The victim was hospitalized for three days but survived the attack.
Police on Wednesday would not release the motive for the beating, but said that it was not sexual in nature as original reported.
Moore was stopped on Tuesday by Sgt. Tom Severance of the Street Crimes Unit, who thought the suspect resembled the person who was seen fleeing after the beating.
During a brief chat near the intersection, Moore made statements about the attack and the sergeant noticed what appeared to be blood stains on the skateboard.
Moore was initially arrested on an unrelated misdemeanor warrant and taken to the police station for further questioning. He later confessed to the committing the crime, Veteran said.
Officers then searched the man's home and found the clothing he wore during the day of the attack