NEW YORK (CBSNewYork) — There has been an increase in the number of sex crimes in the subway system — and as riders grow concerned about safety, more straphangers are becoming subway sleuths.

They’re snapping photos of suspects police say grabbed or groped female victims, others are accused of exposing themselves — actions women say keep them on alert while riding.

“I’m always aware of what’s going on,” one rider told CBS2’s Andrea Grymes.

“Definitely be alert about it. If you see something, say something,” another added.

It seems more people are taking that advice.

That’s how police are explaining the spike in subway sex crimes.

While overall crime underground is down 1.7 percent, the NYPD said the number of subway sex crimes is up 29 percent.

There have been 830 so far this year compared to 641 during the same period last year.

“No one should be subjected to that,” NYPD Transit Chief, Joseph Fox said.

Fox said they’re not surprised by the numbers, and attributed the spike to more victims choosing to come forward.

“I’m confident that we don’t have more sex crimes happening. We have more women who know that we care, who trust the system, and are willing to make that report,” he said.

In mid 2015, Fox said they ramped up their efforts to show the public that they take these incidents seriously.

They’ve made it easier for victims to file reports. The non-profit ‘Hollaback!’ has also been helping — in part by explaining options if a victim wants to come forward.

“You can use our app and elevate it to your local council member. You can map your story. You can go to the MTA website and report it. You can go to a police officer if you feel comfortable, because not everyone feels comfortable doing that,” Hollaback! Deputy Director, Debjani Roy said.

As for taking photos of suspects — police said they do not solicit pictures from the public. They don’t want to put anyone in danger. They said if you have a picture, they’ll take it, but it’s not necessary to investigate one of those crimes.