SAN DIEGO -- A 16-year-old boy who allegedly grabbed a woman by the throat at a trolley station in La Mesa, demanded cash, then kissed the woman before she broke free is facing attempted robbery and sexual assault charges Sunday.

The boy, whose name was being withheld because of his age, and the victim both exited the trolley at the 70th Street stop at 3:48 p.m., La Mesa police Lt. Dan Willis said.

Police also withheld the victim's name.

The victim told police the boy grabbed her from behind, put his hand to her throat and demanding cash, Willis said. The boy said he had a gun and threatened to kill the woman, he said.

The boy forcibly kissed the woman, and she was able to break free and run to a car stopped at a traffic light for help, Willis said.

The boy was booked at juvenile hall on suspicion of attempted robbery, criminal threats, sexual battery and assault with force likely to produce great bodily injury, police said.