gender - How to create an environment in which students can report teacher-student sexual harassment?

I teach physics at a community college in California. A series of female students have told me about sexual harassment by the same tenured male math instructor. Two such incidents went like this.

one incident:

"Professor, I'm having trouble with my homework. Could you give me some help?"

"Sure, let's go have drinks and talk about it."

another incident:

"Professor, can I come to your office hours for help?"

"Sure. You know, my office is soundproof."

I reported the problem to the vice president who handles Title IX. She told me she needed the students to file formal complaints. In one of these incidents, the student was still enrolled in the guy's class. The VP said they could transfer her to another math class to protect her from retribution. I gave the students this information and suggested that they file complaints. A year later, it turns out that they haven't.

I suspect that almost no students at my school know how to go about reporting sexual harassment by a professor, and that almost none know that any measures could be taken to prevent retribution. My school is about to institute a mandatory online orientation, which will cover sexual harassment, but it treats sexual harassment as a general phenomenon and doesn't deal with any of the specific concerns, such as retribution, that arise when it's teacher-on-student harassment. I tried to convince the VP that we should do better outreach on this specific type of sexual harassment, e.g., with posters, including information about how students can be shielded against retribution. This seemed to make her very uncomfortable. I suspect that such a thing would upset interest groups such as the teachers' union.

A related aspect of the problem is that this is a community college, and it's a commuter school, so many students have weak ties to the institution and do not think of themselves primarily as students. The psychology is probably very different from what you see at elite four-year schools where you see this kind of thing.

How do schools create an environment in which students can and do report teacher-student sexual harassment? Are there best practices at other schools (possibly schools similar to mine) that should be emulated?