Police detain teen in fatal beating of 86-year-old woman

California police said they have detained a young man in the apparently random sexual assault and beating death of an 86-year-old woman on a morning walk around a high school track.
Authorities yesterday said Fusako Petrus was killed when she came to the aid of a friend who was the initial target of the attack Wednesday as they exercised on a high school track near Sacramento.
Sacramento County Sheriff's Sgt Tony Turnbull said Petrus and a friend routinely walked around the high school track early in the morning before classes. On Wednesday at about 6 AM, Turnbull said a young man jumped out from behind a baseball backstop and attacked her friend, a 61-year-old woman.

Petrus was several paces ahead of her friend when Petrus heard a commotion and turned back to help, Turnbull said. The 86-year-old brandished a walking stick at the attacker and approached to help her friend. That's when the attacker turned his attention to her, Turnbull said.
Turnbull said both women were sexually assaulted.
Turnbull says an 18-year-old man was arrested later Wednesday in connection with a separate assault. Turnbull said the teen has been booked on suspicion of assaulting another elderly woman later in the day several miles away.
Investigators say the teen is a person of interest in the homicide, but he has not been charged.