A suspect is in custody following the apparent molestation of a nine-year-old girl on an SF-bound BART train. The Chronicle reports that the attack occurred Sunday near Bay Fair Station in San Leandro, and was broken up by family members.

The accused attacker, 26-year-old Marcus Scott Brown, was sitting next to the unidentified child on BART when he allegedly began to touch her leg and buttocks. The girl's family members were able to intervene, and exited the train at approximately 3:40 p.m. at Bay Fair to report the incident.

A witness identified Brown, and he was pulled off the train by police at Coliseum Station. He stands accused of "committing a lewd or lascivious act with a child under 14 years old and criminal threats," the paper reports.

This, tragically, is not the first case of an alleged sexual assault on BART. In 2014 a passenger was accused of groping a woman as he exited a train after she confronted him about a loud boombox, and in October of this year NBC Bay Area reported that a boy was sexually assaulted in a Pittsburg/Bay Point BART station bathroom.

Brown's bail has been set at $150,000.

Related: Man Molests Woman Near Pleasant Hill BART Station