LOS ANGELES (CBSLA) — A woman headed home on the Expo Line late Monday night got an unwelcome show – a man touching and exposing himself through his shorts.

So she responded by taking out her cell phone and recorded video of the man reclining on the seat with his back against the train, one foot up on the seat, his elbow resting on his knee.

The lewd display happened at about 10:45 p.m. Monday out of the Expo Line Sepulveda station. The man wore sunglasses, a black T-shirt and what appeared to be green shorts.

As soon as he exited the train on Bundy, the passenger alerted the train’s conductor, but he said he couldn’t do anything to detain the man. So she filed a police report with the LAPD.

“You’re powerless. And me taking a video and showing the world what we deal with on the daily is taking my power back,” she said. “I’m not a victim of this — he’s the problem and I’m not going to go to bed not talking about it. I’m going to tell everybody.”

The woman, who asked to stay anonymous, is in her 30s, but she said she was speaking up for the younger women and the girls who ride the train.

“This is not one case,” she said. “This is a major issue.”

Others seemed to agree.

“You see naked people get on the bus, you seem them get on the train, you see them playing with [themselves],” one woman told CBS2.

One LAPD sergeant called the video “very disturbing.” Police say they will review security video and put the man’s face on flyers, and possibly deploy undercover officers.

In a statement, Metro says they are aware of the incident and working closely with law enforcement to investigate the incident and find the suspect.

“Metro’s Code of Conduct prohibits lewd acts on its transit system, and Metro has zero tolerance for such behavior,” the statement said.

“We will pursue him with great vigor,” Metro’s Chief of Security Alex Wiggins told reporters Tuesday.

Reports of such incidents can be made to Metro Transit Watch at 888-950-SAFE (7233), while victims of sexual harassment can call Metro’s support hotline at (844) 633-5464.